https://www.youtube.com/watch?v=22ZmmZ67SMY
On 03/06/2026 14:10, Chris Jones wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
This looks horrendous.
How to destroy your reputation in one easy lesson.
John
https://www.youtube.com/watch?v=22ZmmZ67SMY
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
On 03/06/2026 15:39, john larkin wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
When you significantly degrade a couple of parameters
that are important for many users of that part and
don't provide a means of knowing whether you have
the original part or the degraded imitation, then
yes, it is scandalous. Especially when the ECN
tells buyers that the changes will have no impact.
John
https://www.youtube.com/watch?v=22ZmmZ67SMY
On 3/06/2026 11:10 pm, Chris Jones wrote:
<snipped U-tube link>
I hate U-tube and didn't watch it, but I suspect Texas Instruments is
still doing what it did back in 1974 - changing the numbers in the specification of an industry standard part.
At George Kent back in 1974 we had our own part numbers, and the
engineers had the job of setting up a specification sheet and filling in
the numbers and identifying which manufacturers parts could be bought against that part number.
I repeatedly found that the Texas Instruments "industry standard" parts weren't. Their data sheet for that part number would specify looser
limits and poorer typical values than the rest of the industry.
The U-tube link starts off on this this part
https://www.onsemi.com/download/data-sheet/pdf/ne5532-d.pdf
https://www.ti.com/lit/ds/symlink/ne5532.pdf? ts=1780440996215&ref_url=https%253A%252F%252Fwww.google.com%252F
I couldn't see any obvious differences between the TI and the On-Semi
data sheets, but I didn't look all that hard. I don't think that Texas Instruments is destroying their reputation - they are just confirming it.
On Wed, 3 Jun 2026 16:12:27 +0100, John R Walliker
<jrwalliker@gmail.com> wrote:
On 03/06/2026 15:39, john larkin wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
When you significantly degrade a couple of parameters
that are important for many users of that part and
don't provide a means of knowing whether you have
the original part or the degraded imitation, then
yes, it is scandalous. Especially when the ECN
tells buyers that the changes will have no impact.
John
It is impressive that TI keeps parts in production for decades, almost
5 in this case.
This part belongs in the 555 timer and uA741 and 2N3055 generation,
getting creaky before most of my enginers were born. Or before their
parents were born.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
On 03/06/2026 17:04, Bill Sloman wrote:
On 3/06/2026 11:10 pm, Chris Jones wrote:The key differences are that the same TI part number has reduced its
<snipped U-tube link>
I hate U-tube and didn't watch it, but I suspect Texas Instruments is
still doing what it did back in 1974 - changing the numbers in the
specification of an industry standard part.
At George Kent back in 1974 we had our own part numbers, and the
engineers had the job of setting up a specification sheet and filling
in the numbers and identifying which manufacturers parts could be
bought against that part number.
I repeatedly found that the Texas Instruments "industry standard"
parts weren't. Their data sheet for that part number would specify
looser limits and poorer typical values than the rest of the industry.
The U-tube link starts off on this this part
https://www.onsemi.com/download/data-sheet/pdf/ne5532-d.pdf
https://www.ti.com/lit/ds/symlink/ne5532.pdf?
ts=1780440996215&ref_url=https%253A%252F%252Fwww.google.com%252F
I couldn't see any obvious differences between the TI and the On-Semi
data sheets, but I didn't look all that hard. I don't think that Texas
Instruments is destroying their reputation - they are just confirming it.
absolute max supply voltage from 22V to 18V and substantially
reduced the output drive capability.˙ They have removed the spec
for driving into 600 ohm loads.˙ The main use for these parts is in
audio system where driving 600 ohm loads is often a requirement.
I don't have a problem with them stopping the manufacture of an
ancient part and recommending a replacement.˙ They should not
take a completely different design and try to pass it off as the
original and keep the exact same part number they were using
previously.˙ The design really is completely different.
The comparison is between different editions of the same TI
data sheet.
One advantage of using automotive parts is that such changes
are very unlikely.˙ Car manufacturers would not tolerate it.
I was once sitting in on a meeting when a car manufacturer told
a well known semiconductor manufacturer to spend another
USD500k on requalifying a part that had been changed. The semi
manufacturer immediately agreed to do it.
I repeatedly found that the Texas Instruments "industry standard" parts weren't. Their data sheet for that part number would specify looser
limits and poorer typical values than the rest of the industry.
Bill Sloman <bill.sloman@ieee.org> wrote:
[...]
I repeatedly found that the Texas Instruments "industry standard" parts
weren't. Their data sheet for that part number would specify looser
limits and poorer typical values than the rest of the industry.
Perhaps they were telling the truth and the others were stretching it a
bit?
A firm I worked for often quoted specs that were so far below the actual performance that one of our sets almost met spec. with one of the
transistors soldered in backwards. This understatement meant that their
sets had a reputation for always meeting the specification - even after
the customer had tried to 'improve' them.
It was only when the bean-counters began over-ruling the engineers that
sets with better specs on paper but worse or unreliable performance
began to out-sell them.
Chris Jones <lugnut808@spam.yahoo.com> Wrote in message:r
https://www.youtube.com/watch?v=22ZmmZ67SMY
Well you could use the tlv9362.
Cheers
https://www.youtube.com/watch?v=22ZmmZ67SMY
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
Golden ears, my left buttock.
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I >certainly would have when crappy compressed MP3s took over the world.
I was very impressed with mp3 compression first time I heard it
=?UTF-8?Q?Niocl=C3=A1s_P=C3=B3l_Caile=C3=A1n?= de Ghloucester <thanks-to@Taf.com>wrote:
Jan Panteltje <alien@comet.invalid> schreef: >|----------------------------------------------------------------||"I was very impressed with mp3 compression first time I heard it|
|So many audio files on a small memory. |
| |
|Same goes for MPEG compression for video." | >|----------------------------------------------------------------|
Commonly used resources for MPEG-4 audio are defective. Cf. e.g. >HTTP://Gloucester.Insomnia247.NL/FFMPEG_etc/Overcoming_MPEG-4_incompatibility.HTM
(S. HTTP://Gloucester.Insomnia247.NL/ fuer Kontaktdaten!)
liz@poppyrecords.invalid.invalid (Liz Tuddenham)wrote:
Jan Panteltje <alien@comet.invalid> wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
I was very impressed with mp3 compression first time I heard it
...but it doesn't sound so good by the second or third generation.
The difference between the original AIFF file and a first generation mp3
at a moderate compression rate is audible when both are electrically
recorded to a wax cylinder. Sometimes, when a 78 is transferred to mp3,
the results can be excruciating because the algorithm favours the
scratch over the music.
liz@poppyrecords.invalid.invalid (Liz Tuddenham)wrote:
Jan Panteltje <alien@comet.invalid> wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
I was very impressed with mp3 compression first time I heard it
...but it doesn't sound so good by the second or third generation.
The difference between the original AIFF file and a first generation mp3
at a moderate compression rate is audible when both are electrically >recorded to a wax cylinder. Sometimes, when a 78 is transferred to mp3, >the results can be excruciating because the algorithm favours the
scratch over the music.
Sure, but I do not use wax cylinders, have never used those ..
You can hear differences between a wav file and mp3 file made from it.
Legg <legg@nospam.Magma.Ca> wrote: >|-----------------------------------------------|
|"Audio mfrs are pretty paranoid about sources."| >|-----------------------------------------------|
Dear RL,
Why?
With kind regards.
(S. HTTP://Gloucester.Insomnia247.NL/ fuer Kontaktdaten!)
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
Cheers
Phil Hobbs
liz@poppyrecords.invalid.invalid (Liz Tuddenham)wrote:
Jan Panteltje <alien@comet.invalid> wrote:
liz@poppyrecords.invalid.invalid (Liz Tuddenham)wrote:
Jan Panteltje <alien@comet.invalid> wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
I was very impressed with mp3 compression first time I heard it
...but it doesn't sound so good by the second or third generation.
The difference between the original AIFF file and a first generation mp3
at a moderate compression rate is audible when both are electrically
recorded to a wax cylinder. Sometimes, when a 78 is transferred to mp3,
the results can be excruciating because the algorithm favours the
scratch over the music.
Sure, but I do not use wax cylinders, have never used those ..
You can hear differences between a wav file and mp3 file made from it.
My point, which I didn't make very clearly, is that even on 140-year-old >recording technology it is possible to hear the degradation caused by
the mp3 format.
liz@poppyrecords.invalid.invalid (Liz Tuddenham)wrote:
Jan Panteltje <alien@comet.invalid> wrote:
liz@poppyrecords.invalid.invalid (Liz Tuddenham)wrote:
Jan Panteltje <alien@comet.invalid> wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>wrote:I was very impressed with mp3 compression first time I heard it
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world. >> >>
...but it doesn't sound so good by the second or third generation.
The difference between the original AIFF file and a first generation mp3 >> >at a moderate compression rate is audible when both are electrically
recorded to a wax cylinder. Sometimes, when a 78 is transferred to mp3, >> >the results can be excruciating because the algorithm favours the
scratch over the music.
Sure, but I do not use wax cylinders, have never used those ..
You can hear differences between a wav file and mp3 file made from it.
My point, which I didn't make very clearly, is that even on 140-year-old >recording technology it is possible to hear the degradation caused by
the mp3 format.
Clear enough to me.
But that is not a 'normal' situation
Long ago when Sony came out with the Umatic video recorders those had a design problem, the FM frequency discriminator for the video (luminance
not audio) would in case of a tape dropout not keep the last level but
treat it as a 'low frequency' causing a huge spike in the images at that point that did overdrive the electronics
Same sort of work you are doing fixing old audio stuff.
On Thu, 4 Jun 2026 15:22:02 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
Cheers
Phil Hobbs
It's the program material that matters and, often, the context or
venue; not the hardware.
Most distortion still from mikes, loudspeakers and other
electromechanical transducers. The rest is probably in 'your' head.
RL
On 2026-06-05 09:10, legg wrote:
On Thu, 4 Jun 2026 15:22:02 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
Cheers
Phil Hobbs
It's the program material that matters and, often, the context or
venue; not the hardware.
Most distortion still from mikes, loudspeakers and other
electromechanical transducers. The rest is probably in 'your' head.
RL
Exactly. The idea of an "Audio Op Amp", as though the actual
requirements were special, is pretty silly.
(The idea that an 18-nV TL074 is a "low noise" amplifier is even >sillier--it's a good 20 dB off the pace.)
Cheers
Phil Hobbs
On Fri, 5 Jun 2026 13:44:12 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
On 2026-06-05 09:10, legg wrote:
On Thu, 4 Jun 2026 15:22:02 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
Cheers
Phil Hobbs
It's the program material that matters and, often, the context or
venue; not the hardware.
Most distortion still from mikes, loudspeakers and other
electromechanical transducers. The rest is probably in 'your' head.
RL
Exactly. The idea of an "Audio Op Amp", as though the actual
requirements were special, is pretty silly.
(The idea that an 18-nV TL074 is a "low noise" amplifier is even
sillier--it's a good 20 dB off the pace.)
Cheers
Phil Hobbs
There should be a legally binding definition of "high speed" too.
John Larkin <jl@Glen--Canyon.com> wrote: >|-------------------------------------------------------------------|
|"There should be a legally binding definition of "high speed" too."| >|-------------------------------------------------------------------|
The fastest integrated circuits are by no hardware description
language, whereas VHDL stands for Very-High-Speed-Integrated-Circuit >Description Language.
(S. HTTP://Gloucester.Insomnia247.NL/ fuer Kontaktdaten!)
On Wed, 3 Jun 2026 16:12:27 +0100, John R Walliker
<jrwalliker@gmail.com> wrote:
On 03/06/2026 15:39, john larkin wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
When you significantly degrade a couple of parameters
that are important for many users of that part and
don't provide a means of knowing whether you have
the original part or the degraded imitation, then
yes, it is scandalous. ...
... Especially when the ECN
tells buyers that the changes will have no impact.
John
It is impressive that TI keeps parts in production for decades, almost
5 in this case.
This part belongs in the 555 timer and uA741 and 2N3055 generation,
getting creaky before most of my enginers were born. Or before their
parents were born.
https://www.youtube.com/watch?v=22ZmmZ67SMY
On 6/3/26 6:10 AM, Chris Jones wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
The worst I ever saw: A MOSFET that was used in a mixed supply
situation. It switched a 3.3V rail but the gate control came from
12V-driven logic. One day the manufacturer decided in their infinite
wisdom to "improve" it. They added integrated gate protection zeners and >from then on the abs max gate-source voltage became +/-8V instead of the >prior +/-20V. The part number remained the same!
*PHUT* ... *BANG* ... *POOF* ... the company lost hundreds of expensive >boards and since this caused serious overvoltage on the 3.3V supply rail >that fed processors and stuff the boards were not salvageable.
=?UTF-8?Q?Niocl=C3=A1s_P=C3=B3l_Caile=C3=A1n?= de Ghloucester <thanks-to@Taf.com>wrote:
Jan Panteltje <alien@comet.invalid> schreef: >|--------------------------------------------------------------------------------------------||"mediainfo (1) - command line utility to display information about audio/video files"|
|--------------------------------------------------------------------------------------------|
So, Insomnia 24/7 installed mediainfo for me which is an interesting >alternative to ffprobe but the manpage for mediainfo does not explain
a subset of its outputs which it showed me, so maybe I shall need to
download its source instead of only using a packaged binary.
I ran mediainfo and ffprobe on different types of MPEG-4 files in >HTTP://Gloucester.Insomnia247.NL/gardai/Where_are_you_from/
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN >input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN >>> input stage, new is PNP inputs. Unforgivable to not amend the part number >>> in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with >something neat they'd leave out a vital detail in the data sheet.
They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd >almost got a printed circuit layout that worked first time, but I had to >bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN >>>> input stage, new is PNP inputs. Unforgivable to not amend the part number >>>> in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with
something neat they'd leave out a vital detail in the data sheet.
They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN >>>>> input stage, new is PNP inputs. Unforgivable to not amend the part number >>>>> in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with
something neat they'd leave out a vital detail in the data sheet.
They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd >>> almost got a printed circuit layout that worked first time, but I had to >>> bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground.
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN >>>>>> input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with
something neat they'd leave out a vital detail in the data sheet.
They introduced a really nice MOSFET input op-amp and failed to mention >>>> in the data sheet that it had about 10pF input capacitance. For once I'd >>>> almost got a printed circuit layout that worked first time, but I had to >>>> bodge in 2.2pF capacitor in parallel with the feedback resistor to kill >>>> the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground.
Do you use opamps with a ground pin?
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance
of 6.4 pF, whatever that means.
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with >>>>> something neat they'd leave out a vital detail in the data sheet.
They introduced a really nice MOSFET input op-amp and failed to mention >>>>> in the data sheet that it had about 10pF input capacitance. For once I'd >>>>> almost got a printed circuit layout that worked first time, but I had to >>>>> bodge in 2.2pF capacitor in parallel with the feedback resistor to kill >>>>> the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground.
Do you use opamps with a ground pin?
Don't be silly. The ground reference is through the negative rail
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386
It's on page 7 of the data sheet. I was more worried about the
differential capacitance, which is 1.6pF for that part (and pretty
typical). I could try to explain the difference between "differential"
and "common mode" but if you haven't found out about that by now, you >clearly aren't interested in finding out.
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with >>>>>> something neat they'd leave out a vital detail in the data sheet.
They introduced a really nice MOSFET input op-amp and failed to mention >>>>>> in the data sheet that it had about 10pF input capacitance. For once I'd >>>>>> almost got a printed circuit layout that worked first time, but I had to >>>>>> bodge in 2.2pF capacitor in parallel with the feedback resistor to kill >>>>>> the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground.
Do you use opamps with a ground pin?
Don't be silly. The ground reference is through the negative rail
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386
It's on page 7 of the data sheet. I was more worried about the
differential capacitance, which is 1.6pF for that part (and pretty
typical). I could try to explain the difference between "differential"
and "common mode" but if you haven't found out about that by now, you
clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be blamed on differential capacitance and not care about common-mode capacitance?
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>> wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with >>>>>>> something neat they'd leave out a vital detail in the data sheet. >>>>>>> They introduced a really nice MOSFET input op-amp and failed to mention >>>>>>> in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill >>>>>>> the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground.
Do you use opamps with a ground pin?
Don't be silly. The ground reference is through the negative rail
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance >>>> of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386
It's on page 7 of the data sheet. I was more worried about the
differential capacitance, which is 1.6pF for that part (and pretty
typical). I could try to explain the difference between "differential"
and "common mode" but if you haven't found out about that by now, you
clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be blamed on
differential capacitance and not care about common-mode capacitance?
As we?ve discussed before, the differential input capacitance of an op amp >under bias is hard to measure, and the data sheet values are unreliable.
The best way I know of is to put a very small pot directly in series with
the inverting input and look at what happens to the phase margin.
The CM capacitance you can get by doing the same on the noninverting input >and looking at the bandwidth. Feedback bootstraps out the differential >capacitance at low frequency.
Cheers
Phil Hobbs
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>> wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with >>>>>>>> something neat they'd leave out a vital detail in the data sheet. >>>>>>>> They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground.
Do you use opamps with a ground pin?
Don't be silly. The ground reference is through the negative rail
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance >>>>> of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386
It's on page 7 of the data sheet. I was more worried about the
differential capacitance, which is 1.6pF for that part (and pretty
typical). I could try to explain the difference between "differential" >>>> and "common mode" but if you haven't found out about that by now, you >>>> clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be blamed on
differential capacitance and not care about common-mode capacitance?
As we?ve discussed before, the differential input capacitance of an op amp >> under bias is hard to measure, and the data sheet values are unreliable.
The best way I know of is to put a very small pot directly in series with
the inverting input and look at what happens to the phase margin.
The CM capacitance you can get by doing the same on the noninverting input >> and looking at the bandwidth. Feedback bootstraps out the differential
capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C between one
pin and the rails, and sometimes as the c of both pins in parellel to
the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, assumuing
the Spice model is accurate.
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>> wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>> wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old. >>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with >>>>>>>>> something neat they'd leave out a vital detail in the data sheet. >>>>>>>>> They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground.
Do you use opamps with a ground pin?
Don't be silly. The ground reference is through the negative rail
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance >>>>>> of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386
It's on page 7 of the data sheet. I was more worried about the
differential capacitance, which is 1.6pF for that part (and pretty
typical). I could try to explain the difference between "differential" >>>>> and "common mode" but if you haven't found out about that by now, you >>>>> clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an >>>> opamp is.
Any explaination why the peaking in your circuit could be blamed on
differential capacitance and not care about common-mode capacitance?
As we?ve discussed before, the differential input capacitance of an op amp >>> under bias is hard to measure, and the data sheet values are unreliable. >>>
The best way I know of is to put a very small pot directly in series with >>> the inverting input and look at what happens to the phase margin.
The CM capacitance you can get by doing the same on the noninverting input >>> and looking at the bandwidth. Feedback bootstraps out the differential
capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C between one
pin and the rails, and sometimes as the c of both pins in parellel to
the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, assumuing
the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered off, none of
the junction capacitances will be right.
Cheers
Phil Hobbs
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>> wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>>> wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old. >>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with >>>>>>>>>> something neat they'd leave out a vital detail in the data sheet. >>>>>>>>>> They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground.
Do you use opamps with a ground pin?
Don't be silly. The ground reference is through the negative rail
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance >>>>>>> of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386
It's on page 7 of the data sheet. I was more worried about the
differential capacitance, which is 1.6pF for that part (and pretty >>>>>> typical). I could try to explain the difference between "differential" >>>>>> and "common mode" but if you haven't found out about that by now, you >>>>>> clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an >>>>> opamp is.
Any explaination why the peaking in your circuit could be blamed on
differential capacitance and not care about common-mode capacitance? >>>>>
As we?ve discussed before, the differential input capacitance of an op amp >>>> under bias is hard to measure, and the data sheet values are unreliable. >>>>
The best way I know of is to put a very small pot directly in series with >>>> the inverting input and look at what happens to the phase margin.
The CM capacitance you can get by doing the same on the noninverting input >>>> and looking at the bandwidth. Feedback bootstraps out the differential >>>> capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C between one
pin and the rails, and sometimes as the c of both pins in parellel to
the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, assumuing
the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered off, none of
the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model
converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step,
through a 1M resistor. The output is a nice exponential with tau =
6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a
follower.
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>> wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>> wrote:
On 7/06/2026 1:57 am, john larkin wrote:Do you use opamps with a ground pin?
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old. >>>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with
something neat they'd leave out a vital detail in the data sheet. >>>>>>>>>>> They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground. >>>>>>>>
Don't be silly. The ground reference is through the negative rail >>>>>>>
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance >>>>>>>> of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386
It's on page 7 of the data sheet. I was more worried about the
differential capacitance, which is 1.6pF for that part (and pretty >>>>>>> typical). I could try to explain the difference between "differential" >>>>>>> and "common mode" but if you haven't found out about that by now, you >>>>>>> clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an >>>>>> opamp is.
Any explaination why the peaking in your circuit could be blamed on >>>>>> differential capacitance and not care about common-mode capacitance? >>>>>>
As we?ve discussed before, the differential input capacitance of an op amp
under bias is hard to measure, and the data sheet values are unreliable. >>>>>
The best way I know of is to put a very small pot directly in series with >>>>> the inverting input and look at what happens to the phase margin.
The CM capacitance you can get by doing the same on the noninverting input
and looking at the bandwidth. Feedback bootstraps out the differential >>>>> capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C between one
pin and the rails, and sometimes as the c of both pins in parellel to
the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, assumuing >>>> the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered off, none of >>> the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model
converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step,
through a 1M resistor. The output is a nice exponential with tau =
6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a
follower.
It doesn't. There's a collector/base or gate/drain capacitance that has
to be charged up if the input moves vis-a-vis local ground (in this case
the local rail voltages inside the chip). There are heroic measures that
can minimise this - essentially floating the power rails though they
move too slowly to be of all that much help - but regular followers
don't use them.
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>> wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>>> wrote:
On 7/06/2026 1:57 am, john larkin wrote:Do you use opamps with a ground pin?
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old. >>>>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with
something neat they'd leave out a vital detail in the data sheet. >>>>>>>>>>>> They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground. >>>>>>>>>
Don't be silly. The ground reference is through the negative rail >>>>>>>>
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386
It's on page 7 of the data sheet. I was more worried about the >>>>>>>> differential capacitance, which is 1.6pF for that part (and pretty >>>>>>>> typical). I could try to explain the difference between "differential" >>>>>>>> and "common mode" but if you haven't found out about that by now, you >>>>>>>> clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an >>>>>>> opamp is.
Any explaination why the peaking in your circuit could be blamed on >>>>>>> differential capacitance and not care about common-mode capacitance? >>>>>>>
As we?ve discussed before, the differential input capacitance of an op amp
under bias is hard to measure, and the data sheet values are unreliable. >>>>>>
The best way I know of is to put a very small pot directly in series with
the inverting input and look at what happens to the phase margin.
The CM capacitance you can get by doing the same on the noninverting input
and looking at the bandwidth. Feedback bootstraps out the differential >>>>>> capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C between one >>>>> pin and the rails, and sometimes as the c of both pins in parellel to >>>>> the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, assumuing >>>>> the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered off, none of >>>> the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model
converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step,
through a 1M resistor. The output is a nice exponential with tau =
6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a
follower.
It doesn't. There's a collector/base or gate/drain capacitance that has
to be charged up if the input moves vis-a-vis local ground (in this case
the local rail voltages inside the chip). There are heroic measures that
can minimise this - essentially floating the power rails though they
move too slowly to be of all that much help - but regular followers
don't use them.
Imagine three caps.
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>> wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>>> wrote:
On 7/06/2026 1:57 am, john larkin wrote:Do you use opamps with a ground pin?
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old. >>>>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with
something neat they'd leave out a vital detail in the data sheet. >>>>>>>>>>>> They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground. >>>>>>>>>
Don't be silly. The ground reference is through the negative rail >>>>>>>>
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386
It's on page 7 of the data sheet. I was more worried about the >>>>>>>> differential capacitance, which is 1.6pF for that part (and pretty >>>>>>>> typical). I could try to explain the difference between "differential" >>>>>>>> and "common mode" but if you haven't found out about that by now, you >>>>>>>> clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an >>>>>>> opamp is.
Any explaination why the peaking in your circuit could be blamed on >>>>>>> differential capacitance and not care about common-mode capacitance? >>>>>>>
As we?ve discussed before, the differential input capacitance of an op amp
under bias is hard to measure, and the data sheet values are unreliable. >>>>>>
The best way I know of is to put a very small pot directly in series with
the inverting input and look at what happens to the phase margin.
The CM capacitance you can get by doing the same on the noninverting input
and looking at the bandwidth. Feedback bootstraps out the differential >>>>>> capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C between one >>>>> pin and the rails, and sometimes as the c of both pins in parellel to >>>>> the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, assumuing >>>>> the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered off, none of >>>> the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model
converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step,
through a 1M resistor. The output is a nice exponential with tau =
6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a
follower.
It doesn't. There's a collector/base or gate/drain capacitance that has
to be charged up if the input moves vis-a-vis local ground (in this case
the local rail voltages inside the chip). There are heroic measures that
can minimise this - essentially floating the power rails though they
move too slowly to be of all that much help - but regular followers
don't use them.
Imagine three caps.
C1 is inverting input to all the virtual grounds.
C2 is n.i. input cap to ground
C3 is between the two inputs.
TI calls C1 the common-mode capacitance Zic
They also call C2 the same thing.
They call C3 the differential capacitance Zid.
My sim measured only C2, because both C1 and C3 followed the input so
were bootstrapped out of existence.
C1 and C2 are each spec'd at 6.4 pF. I estmated 6.45 from my sim,
eyeballing tau.
OPA197 has a lots of protections and integral EMI filtering, which
adds capacitance. Nice safe gumdrop. One can drive the inputs modestly
past the rails and it doesn't go crazy. It makes a decent RRIO
comparator too.
Some people think the "common mode capacitance" is C1 + C2. TI
doesn't.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
On 7/06/2026 11:19 pm, john larkin wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>> wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:Do you use opamps with a ground pin?
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old. >>>>>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with
something neat they'd leave out a vital detail in the data sheet. >>>>>>>>>>>>> They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground. >>>>>>>>>>
Don't be silly. The ground reference is through the negative rail >>>>>>>>>
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386 >>>>>>>>>
It's on page 7 of the data sheet. I was more worried about the >>>>>>>>> differential capacitance, which is 1.6pF for that part (and pretty >>>>>>>>> typical). I could try to explain the difference between "differential"
and "common mode" but if you haven't found out about that by now, you >>>>>>>>> clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an >>>>>>>> opamp is.
Any explaination why the peaking in your circuit could be blamed on >>>>>>>> differential capacitance and not care about common-mode capacitance? >>>>>>>>
As we?ve discussed before, the differential input capacitance of an op amp
under bias is hard to measure, and the data sheet values are unreliable.
The best way I know of is to put a very small pot directly in series with
the inverting input and look at what happens to the phase margin. >>>>>>>
The CM capacitance you can get by doing the same on the noninverting input
and looking at the bandwidth. Feedback bootstraps out the differential >>>>>>> capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C between one >>>>>> pin and the rails, and sometimes as the c of both pins in parellel to >>>>>> the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, assumuing >>>>>> the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered off, none of >>>>> the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model
converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step,
through a 1M resistor. The output is a nice exponential with tau =
6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a
follower.
It doesn't. There's a collector/base or gate/drain capacitance that has
to be charged up if the input moves vis-a-vis local ground (in this case >>> the local rail voltages inside the chip). There are heroic measures that >>> can minimise this - essentially floating the power rails though they
move too slowly to be of all that much help - but regular followers
don't use them.
Imagine three caps.
Probably not a useful exercise, judging from the unhelpful observations
that followed, which I've snipped.
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>> wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:Do you use opamps with a ground pin?
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
They changed the process on a part that's 47 years old. >>>>>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with
something neat they'd leave out a vital detail in the data sheet. >>>>>>>>>>>>> They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground. >>>>>>>>>>
Don't be silly. The ground reference is through the negative rail >>>>>>>>>
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386 >>>>>>>>>
It's on page 7 of the data sheet. I was more worried about the >>>>>>>>> differential capacitance, which is 1.6pF for that part (and pretty >>>>>>>>> typical). I could try to explain the difference between "differential"
and "common mode" but if you haven't found out about that by now, you >>>>>>>>> clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an >>>>>>>> opamp is.
Any explaination why the peaking in your circuit could be blamed on >>>>>>>> differential capacitance and not care about common-mode capacitance? >>>>>>>>
As we?ve discussed before, the differential input capacitance of an op amp
under bias is hard to measure, and the data sheet values are unreliable.
The best way I know of is to put a very small pot directly in series with
the inverting input and look at what happens to the phase margin. >>>>>>>
The CM capacitance you can get by doing the same on the noninverting input
and looking at the bandwidth. Feedback bootstraps out the differential >>>>>>> capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C between one >>>>>> pin and the rails, and sometimes as the c of both pins in parellel to >>>>>> the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, assumuing >>>>>> the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered off, none of >>>>> the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model
converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step,
through a 1M resistor. The output is a nice exponential with tau =
6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a
follower.
It doesn't. There's a collector/base or gate/drain capacitance that has >>> to be charged up if the input moves vis-a-vis local ground (in this case >>> the local rail voltages inside the chip). There are heroic measures that >>> can minimise this - essentially floating the power rails though they
move too slowly to be of all that much help - but regular followers
don't use them.
Imagine three caps.
C1 is inverting input to all the virtual grounds.
C2 is n.i. input cap to ground
C3 is between the two inputs.
TI calls C1 the common-mode capacitance Zic
They also call C2 the same thing.
They call C3 the differential capacitance Zid.
My sim measured only C2, because both C1 and C3 followed the input so
were bootstrapped out of existence.
C1 and C2 are each spec'd at 6.4 pF. I estmated 6.45 from my sim,
eyeballing tau.
OPA197 has a lots of protections and integral EMI filtering, which
adds capacitance. Nice safe gumdrop. One can drive the inputs modestly
past the rails and it doesn't go crazy. It makes a decent RRIO
comparator too.
Some people think the "common mode capacitance" is C1 + C2. TI
doesn't.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
Thanks, that makes sense, beforehand I too would have said it was C1+C2
On Sun, 7 Jun 2026 14:40:04 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>>> wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:Do you use opamps with a ground pin?
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY >>>>>>>>>>>>>>>>>They changed the process on a part that's 47 years old. >>>>>>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with
something neat they'd leave out a vital detail in the data sheet.
They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground. >>>>>>>>>>>
Don't be silly. The ground reference is through the negative rail >>>>>>>>>>
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386 >>>>>>>>>>
It's on page 7 of the data sheet. I was more worried about the >>>>>>>>>> differential capacitance, which is 1.6pF for that part (and pretty >>>>>>>>>> typical). I could try to explain the difference between "differential"
and "common mode" but if you haven't found out about that by now, you
clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be blamed on >>>>>>>>> differential capacitance and not care about common-mode capacitance? >>>>>>>>>
As we?ve discussed before, the differential input capacitance of an op amp
under bias is hard to measure, and the data sheet values are unreliable.
The best way I know of is to put a very small pot directly in series with
the inverting input and look at what happens to the phase margin. >>>>>>>>
The CM capacitance you can get by doing the same on the noninverting input
and looking at the bandwidth. Feedback bootstraps out the differential
capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C between one >>>>>>> pin and the rails, and sometimes as the c of both pins in parellel to >>>>>>> the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, assumuing >>>>>>> the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered off, none of >>>>>> the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model
converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step,
through a 1M resistor. The output is a nice exponential with tau =
6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a
follower.
It doesn't. There's a collector/base or gate/drain capacitance that has >>>> to be charged up if the input moves vis-a-vis local ground (in this case >>>> the local rail voltages inside the chip). There are heroic measures that >>>> can minimise this - essentially floating the power rails though they
move too slowly to be of all that much help - but regular followers
don't use them.
Imagine three caps.
C1 is inverting input to all the virtual grounds.
C2 is n.i. input cap to ground
C3 is between the two inputs.
TI calls C1 the common-mode capacitance Zic
They also call C2 the same thing.
They call C3 the differential capacitance Zid.
My sim measured only C2, because both C1 and C3 followed the input so
were bootstrapped out of existence.
C1 and C2 are each spec'd at 6.4 pF. I estmated 6.45 from my sim,
eyeballing tau.
OPA197 has a lots of protections and integral EMI filtering, which
adds capacitance. Nice safe gumdrop. One can drive the inputs modestly
past the rails and it doesn't go crazy. It makes a decent RRIO
comparator too.
Some people think the "common mode capacitance" is C1 + C2. TI
doesn't.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
Thanks, that makes sense, beforehand I too would have said it was C1+C2
It's interesting, but one can just Spice actual circuits and see what >happens. Understanding the capacitances helps make the initial opamp >selections to sim.
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
Cheers
Phil Hobbs
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
Cheers
Phil Hobbs
TI managed it much better with the 324 and 339. They brought out the B >versions with their own datasheets and kept making the old ones.
I wonder if that process has gone away too. It must be a drag keeping
creaky old litho tools and 5- inch wafer processes alive. Probably duct
tape on top of JB Weld.
On Sun, 7 Jun 2026 18:49:05 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
RL
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
Cheers
Phil Hobbs
TI managed it much better with the 324 and 339. They brought out the B
versions with their own datasheets and kept making the old ones.
In the original National parts, all four channels would go bonkers if
any input went slightly below ground.
Nice. We?ll have to find a use for it.
I wonder if that process has gone away too. It must be a drag keeping
creaky old litho tools and 5- inch wafer processes alive. Probably duct
tape on top of JB Weld.
And the test sets.
A support guy said "That's an old Burr-Brown part. We don't know much
about those."
Speaking of TI, this is incredible:
https://www.ti.com/product/ADS131M02
Under $2.
On Sun, 7 Jun 2026 14:40:04 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>>> wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:Do you use opamps with a ground pin?
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY >>>>>>>>>>>>>>>>>They changed the process on a part that's 47 years old. >>>>>>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with
something neat they'd leave out a vital detail in the data sheet.
They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground. >>>>>>>>>>>
Don't be silly. The ground reference is through the negative rail >>>>>>>>>>
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386 >>>>>>>>>>
It's on page 7 of the data sheet. I was more worried about the >>>>>>>>>> differential capacitance, which is 1.6pF for that part (and pretty >>>>>>>>>> typical). I could try to explain the difference between "differential"
and "common mode" but if you haven't found out about that by now, you
clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be blamed on >>>>>>>>> differential capacitance and not care about common-mode capacitance? >>>>>>>>>
As we?ve discussed before, the differential input capacitance of an op amp
under bias is hard to measure, and the data sheet values are unreliable.
The best way I know of is to put a very small pot directly in series with
the inverting input and look at what happens to the phase margin. >>>>>>>>
The CM capacitance you can get by doing the same on the noninverting input
and looking at the bandwidth. Feedback bootstraps out the differential
capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C between one >>>>>>> pin and the rails, and sometimes as the c of both pins in parellel to >>>>>>> the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, assumuing >>>>>>> the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered off, none of >>>>>> the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model
converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step,
through a 1M resistor. The output is a nice exponential with tau =
6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a
follower.
It doesn't. There's a collector/base or gate/drain capacitance that has >>>> to be charged up if the input moves vis-a-vis local ground (in this case >>>> the local rail voltages inside the chip). There are heroic measures that >>>> can minimise this - essentially floating the power rails though they
move too slowly to be of all that much help - but regular followers
don't use them.
Imagine three caps.
C1 is inverting input to all the virtual grounds.
C2 is n.i. input cap to ground
C3 is between the two inputs.
TI calls C1 the common-mode capacitance Zic
They also call C2 the same thing.
They call C3 the differential capacitance Zid.
My sim measured only C2, because both C1 and C3 followed the input so
were bootstrapped out of existence.
C1 and C2 are each spec'd at 6.4 pF. I estmated 6.45 from my sim,
eyeballing tau.
OPA197 has a lots of protections and integral EMI filtering, which
adds capacitance. Nice safe gumdrop. One can drive the inputs modestly
past the rails and it doesn't go crazy. It makes a decent RRIO
comparator too.
Some people think the "common mode capacitance" is C1 + C2. TI
doesn't.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
Thanks, that makes sense, beforehand I too would have said it was C1+C2
It's interesting, but one can just Spice actual circuits and see what happens. Understanding the capacitances helps make the initial opamp selections to sim.
On 8/06/2026 2:04 am, john larkin wrote:
On Sun, 7 Jun 2026 14:40:04 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:Do you use opamps with a ground pin?
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet >>>>>>>>>>>>>>>> <erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY >>>>>>>>>>>>>>>>>>They changed the process on a part that's 47 years old. >>>>>>>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different >>>>>>>>>>>>>>>>> product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not >>>>>>>>>>>>>>>>> amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they >>>>>>>>>>>>>>> came up with
something neat they'd leave out a vital detail in the >>>>>>>>>>>>>>> data sheet.
They introduced a really nice MOSFET input op-amp and >>>>>>>>>>>>>>> failed to mention
in the data sheet that it had about 10pF input
capacitance. For once I'd
almost got a printed circuit layout that worked first >>>>>>>>>>>>>>> time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback >>>>>>>>>>>>>>> resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground. >>>>>>>>>>>>
Don't be silly. The ground reference is through the negative >>>>>>>>>>> rail
My favorite gumdrop opamp, OPA197, has a typ "common mode" >>>>>>>>>>>> capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386 >>>>>>>>>>>
It's on page 7 of the data sheet. I was more worried about the >>>>>>>>>>> differential capacitance, which is 1.6pF for that part (and >>>>>>>>>>> pretty
typical). I could try to explain the difference between >>>>>>>>>>> "differential"
and "common mode" but if you haven't found out about that by >>>>>>>>>>> now, you
clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode
capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be >>>>>>>>>> blamed on
differential capacitance and not care about common-mode
capacitance?
As we?ve discussed before, the differential input capacitance >>>>>>>>> of an op amp
under bias is hard to measure, and the data sheet values are >>>>>>>>> unreliable.
The best way I know of is to put a very small pot directly in >>>>>>>>> series with
the inverting input and look at what happens to the phase margin. >>>>>>>>>
The CM capacitance you can get by doing the same on the
noninverting input
and looking at the bandwidth.˙ Feedback bootstraps out the
differential
capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C between >>>>>>>> one
pin and the rails, and sometimes as the c of both pins in
parellel to
the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does,
assumuing
the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered off, >>>>>>> none of
the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model
converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step, >>>>>> through a 1M resistor. The output is a nice exponential with tau = >>>>>> 6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a >>>>>> follower.
It doesn't. There's a collector/base or gate/drain capacitance that >>>>> has
to be charged up if the input moves vis-a-vis local ground (in this >>>>> case
the local rail voltages inside the chip). There are heroic measures >>>>> that
can minimise this - essentially floating the power rails though they >>>>> move too slowly to be of all that much help - but regular followers
don't use them.
Imagine three caps.
My sim measured only C2, because both C1 and C3 followed the input so
were bootstrapped out of existence.
Thanks, that makes sense, beforehand I too would have said it was C1+C2
It's interesting, but one can just Spice actual circuits and see what
happens. Understanding the capacitances helps make the initial opamp
selections to sim.
A frustrating thing is that the opamp manufacturer has an exceedingly accurate spice model of the part that their designers created in order
to optimise and verify the design, but the company won't give that one
to the public.
The schematic in the datasheet is often drawn by
marketing people who have never discussed it with the design engineers,
let alone seen the real schematic, and is sometimes a source of great amusement to the actual designers.
possibly created in a similar manner, but possibly corrected based on
some measurements by apps engineers or based on complaints from
customers. Meanwhile the really accurate model sits on some internal
server being ignored while the design engineers have moved on to some
other product.
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
TI managed it much better with the 324 and 339. They brought out the B versions with their own datasheets and kept making the old ones.
I wonder if that process has gone away too. It must be a drag keeping
creaky old litho tools and 5- inch wafer processes alive. Probably duct
tape on top of JB Weld.
On 8/06/2026 12:12 pm, Chris Jones wrote:
On 8/06/2026 2:04 am, john larkin wrote:
On Sun, 7 Jun 2026 14:40:04 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:Do you use opamps with a ground pin?
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet >>>>>>>>>>>>>>>>> <erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY >>>>>>>>>>>>>>>>>>>They changed the process on a part that's 47 years old. >>>>>>>>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different >>>>>>>>>>>>>>>>>> product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not >>>>>>>>>>>>>>>>>> amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they >>>>>>>>>>>>>>>> came up with
something neat they'd leave out a vital detail in the >>>>>>>>>>>>>>>> data sheet.
They introduced a really nice MOSFET input op-amp and >>>>>>>>>>>>>>>> failed to mention
in the data sheet that it had about 10pF input >>>>>>>>>>>>>>>> capacitance. For once I'd
almost got a printed circuit layout that worked first >>>>>>>>>>>>>>>> time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback >>>>>>>>>>>>>>>> resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground. >>>>>>>>>>>>>
Don't be silly. The ground reference is through the negative >>>>>>>>>>>> rail
My favorite gumdrop opamp, OPA197, has a typ "common mode" >>>>>>>>>>>>> capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386 >>>>>>>>>>>>
It's on page 7 of the data sheet. I was more worried about the >>>>>>>>>>>> differential capacitance, which is 1.6pF for that part (and >>>>>>>>>>>> pretty
typical). I could try to explain the difference between >>>>>>>>>>>> "differential"
and "common mode" but if you haven't found out about that by >>>>>>>>>>>> now, you
clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode
capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be >>>>>>>>>>> blamed on
differential capacitance and not care about common-mode >>>>>>>>>>> capacitance?
As we?ve discussed before, the differential input capacitance >>>>>>>>>> of an op amp
under bias is hard to measure, and the data sheet values are >>>>>>>>>> unreliable.
The best way I know of is to put a very small pot directly in >>>>>>>>>> series with
the inverting input and look at what happens to the phase margin. >>>>>>>>>>
The CM capacitance you can get by doing the same on the
noninverting input
and looking at the bandwidth.˙ Feedback bootstraps out the >>>>>>>>>> differential
capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C
between one
pin and the rails, and sometimes as the c of both pins in
parellel to
the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, >>>>>>>>> assumuing
the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered off, >>>>>>>> none of
the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model
converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step, >>>>>>> through a 1M resistor. The output is a nice exponential with tau = >>>>>>> 6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a >>>>>>> follower.
It doesn't. There's a collector/base or gate/drain capacitance
that has
to be charged up if the input moves vis-a-vis local ground (in
this case
the local rail voltages inside the chip). There are heroic
measures that
can minimise this - essentially floating the power rails though they >>>>>> move too slowly to be of all that much help - but regular followers >>>>>> don't use them.
Imagine three caps.
Don't bother.
<snip>
My sim measured only C2, because both C1 and C3 followed the input so >>>>> were bootstrapped out of existence.
Whatever that is supposed to mean.
<snip>
Thanks, that makes sense, beforehand I too would have said it was C1+C2 >>>It's interesting, but one can just Spice actual circuits and see what
happens. Understanding the capacitances helps make the initial opamp
selections to sim.
If the simulation is any good. The published simulation models are
mostly behavioral, and precise enough for the purpose the marketing
people had in mind.
A frustrating thing is that the opamp manufacturer has an exceedingly
accurate spice model of the part that their designers created in order
to optimise and verify the design, but the company won't give that one
to the public.
It's "commercial in confidence" because it exposes a lot of the detailed design of the chip being simulated.
The schematic in the datasheet is often drawn by marketing people who
have never discussed it with the design engineers, let alone seen the
real schematic, and is sometimes a source of great amusement to the
actual designers.
Commercial secrecy pretty much demands that.
˙The public spice model is quite
possibly created in a similar manner, but possibly corrected based on
some measurements by apps engineers or based on complaints from
customers. Meanwhile the really accurate model sits on some internal
server being ignored while the design engineers have moved on to some
other product.
It's not ignored - just too revealing to be made public.
On 8/06/2026 2:04 am, john larkin wrote:
On Sun, 7 Jun 2026 14:40:04 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:Do you use opamps with a ground pin?
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet >>>>>>>>>>>>>>>> <erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY >>>>>>>>>>>>>>>>>>They changed the process on a part that's 47 years old. >>>>>>>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
More than a process change, it is a whole different product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they came up with
something neat they'd leave out a vital detail in the data sheet.
They introduced a really nice MOSFET input op-amp and failed to mention
in the data sheet that it had about 10pF input capacitance. For once I'd
almost got a printed circuit layout that worked first time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to ground. >>>>>>>>>>>>
Don't be silly. The ground reference is through the negative rail >>>>>>>>>>>
My favorite gumdrop opamp, OPA197, has a typ "common mode" capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386 >>>>>>>>>>>
It's on page 7 of the data sheet. I was more worried about the >>>>>>>>>>> differential capacitance, which is 1.6pF for that part (and pretty >>>>>>>>>>> typical). I could try to explain the difference between "differential"
and "common mode" but if you haven't found out about that by now, you
clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be blamed on >>>>>>>>>> differential capacitance and not care about common-mode capacitance? >>>>>>>>>>
As we?ve discussed before, the differential input capacitance of an op amp
under bias is hard to measure, and the data sheet values are unreliable.
The best way I know of is to put a very small pot directly in series with
the inverting input and look at what happens to the phase margin. >>>>>>>>>
The CM capacitance you can get by doing the same on the noninverting input
and looking at the bandwidth. Feedback bootstraps out the differential
capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C between one >>>>>>>> pin and the rails, and sometimes as the c of both pins in parellel to >>>>>>>> the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, assumuing >>>>>>>> the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered off, none of
the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model
converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step, >>>>>> through a 1M resistor. The output is a nice exponential with tau = >>>>>> 6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a >>>>>> follower.
It doesn't. There's a collector/base or gate/drain capacitance that has >>>>> to be charged up if the input moves vis-a-vis local ground (in this case >>>>> the local rail voltages inside the chip). There are heroic measures that >>>>> can minimise this - essentially floating the power rails though they >>>>> move too slowly to be of all that much help - but regular followers
don't use them.
Imagine three caps.
C1 is inverting input to all the virtual grounds.
C2 is n.i. input cap to ground
C3 is between the two inputs.
TI calls C1 the common-mode capacitance Zic
They also call C2 the same thing.
They call C3 the differential capacitance Zid.
My sim measured only C2, because both C1 and C3 followed the input so
were bootstrapped out of existence.
C1 and C2 are each spec'd at 6.4 pF. I estmated 6.45 from my sim,
eyeballing tau.
OPA197 has a lots of protections and integral EMI filtering, which
adds capacitance. Nice safe gumdrop. One can drive the inputs modestly >>>> past the rails and it doesn't go crazy. It makes a decent RRIO
comparator too.
Some people think the "common mode capacitance" is C1 + C2. TI
doesn't.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
Thanks, that makes sense, beforehand I too would have said it was C1+C2
It's interesting, but one can just Spice actual circuits and see what
happens. Understanding the capacitances helps make the initial opamp
selections to sim.
A frustrating thing is that the opamp manufacturer has an exceedingly >accurate spice model of the part that their designers created in order
to optimise and verify the design, but the company won't give that one
to the public. The schematic in the datasheet is often drawn by
marketing people who have never discussed it with the design engineers,
let alone seen the real schematic, and is sometimes a source of great >amusement to the actual designers. The public spice model is quite
possibly created in a similar manner, but possibly corrected based on
some measurements by apps engineers or based on complaints from
customers. Meanwhile the really accurate model sits on some internal
server being ignored while the design engineers have moved on to some
other product.
On 8/06/2026 3:36 pm, Bill Sloman wrote:
On 8/06/2026 12:12 pm, Chris Jones wrote:
On 8/06/2026 2:04 am, john larkin wrote:
On Sun, 7 Jun 2026 14:40:04 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>> wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman >>>>>>>>>>>>>>>> <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet >>>>>>>>>>>>>>>>>> <erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote: >>>>>>>>>>>>>>>>>>>> On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY >>>>>>>>>>>>>>>>>>>>They changed the process on a part that's 47 years old. >>>>>>>>>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center >>>>>>>>>>>>>>>>>>>> Lunatic Fringe Electronics
More than a process change, it is a whole different >>>>>>>>>>>>>>>>>>> product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not >>>>>>>>>>>>>>>>>>> amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they >>>>>>>>>>>>>>>>> came up with
something neat they'd leave out a vital detail in the >>>>>>>>>>>>>>>>> data sheet.
They introduced a really nice MOSFET input op-amp and >>>>>>>>>>>>>>>>> failed to mention
in the data sheet that it had about 10pF input >>>>>>>>>>>>>>>>> capacitance. For once I'd
almost got a printed circuit layout that worked first >>>>>>>>>>>>>>>>> time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback >>>>>>>>>>>>>>>>> resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to >>>>>>>>>>>>>>> ground.
Do you use opamps with a ground pin?
Don't be silly. The ground reference is through the >>>>>>>>>>>>> negative rail
My favorite gumdrop opamp, OPA197, has a typ "common mode" >>>>>>>>>>>>>> capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386 >>>>>>>>>>>>>
It's on page 7 of the data sheet. I was more worried about the >>>>>>>>>>>>> differential capacitance, which is 1.6pF for that part (and >>>>>>>>>>>>> pretty
typical). I could try to explain the difference between >>>>>>>>>>>>> "differential"
and "common mode" but if you haven't found out about that >>>>>>>>>>>>> by now, you
clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode
capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be >>>>>>>>>>>> blamed on
differential capacitance and not care about common-mode >>>>>>>>>>>> capacitance?
As we?ve discussed before, the differential input capacitance >>>>>>>>>>> of an op amp
under bias is hard to measure, and the data sheet values are >>>>>>>>>>> unreliable.
The best way I know of is to put a very small pot directly in >>>>>>>>>>> series with
the inverting input and look at what happens to the phase >>>>>>>>>>> margin.
The CM capacitance you can get by doing the same on the >>>>>>>>>>> noninverting input
and looking at the bandwidth.˙ Feedback bootstraps out the >>>>>>>>>>> differential
capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C
between one
pin and the rails, and sometimes as the c of both pins in >>>>>>>>>> parellel to
the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, >>>>>>>>>> assumuing
the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered >>>>>>>>> off, none of
the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model >>>>>>>> converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step, >>>>>>>> through a 1M resistor. The output is a nice exponential with tau = >>>>>>>> 6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a >>>>>>>> follower.
It doesn't. There's a collector/base or gate/drain capacitance
that has
to be charged up if the input moves vis-a-vis local ground (in
this case
the local rail voltages inside the chip). There are heroic
measures that
can minimise this - essentially floating the power rails though they >>>>>>> move too slowly to be of all that much help - but regular followers >>>>>>> don't use them.
Imagine three caps.
Don't bother.
<snip>
My sim measured only C2, because both C1 and C3 followed the input so >>>>>> were bootstrapped out of existence.
Whatever that is supposed to mean.
<snip>
Thanks, that makes sense, beforehand I too would have said it was
C1+C2
It's interesting, but one can just Spice actual circuits and see what
happens. Understanding the capacitances helps make the initial opamp
selections to sim.
If the simulation is any good. The published simulation models are
mostly behavioral, and precise enough for the purpose the marketing
people had in mind.
A frustrating thing is that the opamp manufacturer has an exceedingly
accurate spice model of the part that their designers created in
order to optimise and verify the design, but the company won't give
that one to the public.
It's "commercial in confidence" because it exposes a lot of the
detailed design of the chip being simulated.
The schematic in the datasheet is often drawn by marketing people who
have never discussed it with the design engineers, let alone seen the
real schematic, and is sometimes a source of great amusement to the
actual designers.
Commercial secrecy pretty much demands that.
There are several commercial lab services that will take a competitor's
chip that you obtained, (including mixed-signal designs much more complicated than an op-amp), and reverse engineer it for a smallish fee. They provide detailed schematics and layout. It is much cheaper than a
mask set and well within the means of every competitor. It isn't usually that interesting except perhaps e.g. to see whether one's patent is
being infringed.
˙˙The public spice model is quite
possibly created in a similar manner, but possibly corrected based on
some measurements by apps engineers or based on complaints from
customers. Meanwhile the really accurate model sits on some internal
server being ignored while the design engineers have moved on to some
other product.
It's not ignored - just too revealing to be made public.
Keeping the best spice models secret from customers achieves little, as
any competitor would already have full schematics if they wanted them.
Perhaps the non-technical management and shareholders don't appreciate
this, or don't appreciate the significant extra value to the customer of having a simulation model that is really accurate.
On Mon, 8 Jun 2026 12:12:27 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
On 8/06/2026 2:04 am, john larkin wrote:
On Sun, 7 Jun 2026 14:40:04 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet >>>>>>>>>>>>>>>>> <erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
Thanks, that makes sense, beforehand I too would have said it was C1+C2 >>>It's interesting, but one can just Spice actual circuits and see what
happens. Understanding the capacitances helps make the initial opamp
selections to sim.
A frustrating thing is that the opamp manufacturer has an exceedingly
accurate spice model of the part that their designers created in order
to optimise and verify the design, but the company won't give that one
to the public. The schematic in the datasheet is often drawn by
marketing people who have never discussed it with the design engineers,
let alone seen the real schematic, and is sometimes a source of great
amusement to the actual designers. The public spice model is quite
possibly created in a similar manner, but possibly corrected based on
some measurements by apps engineers or based on complaints from
customers. Meanwhile the really accurate model sits on some internal
server being ignored while the design engineers have moved on to some
other product.
The LT Spice library part models seem to be pretty good. They are
behavioral models, and I assume that they have internal,
semiconductor-level models, that run really slow.
I found one LTC part that, with no power connected, would generate a
teravolt on one of its pins. Free energy! Obviously they use ideal
current sources in the public model.
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to
be close to particularly good brains.
On 8/06/2026 3:36 pm, Bill Sloman wrote:
On 8/06/2026 12:12 pm, Chris Jones wrote:
On 8/06/2026 2:04 am, john larkin wrote:
On Sun, 7 Jun 2026 14:40:04 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>> wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman >>>>>>>>>>>>>>>> <bill.sloman@ieee.org>
wrote:
On 6/06/2026 10:53 pm, john larkin wrote:
On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet >>>>>>>>>>>>>>>>>> <erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote: >>>>>>>>>>>>>>>>>>>> On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY >>>>>>>>>>>>>>>>>>>>They changed the process on a part that's 47 years old. >>>>>>>>>>>>>>>>>>>>
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center >>>>>>>>>>>>>>>>>>>> Lunatic Fringe Electronics
More than a process change, it is a whole different >>>>>>>>>>>>>>>>>>> product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not >>>>>>>>>>>>>>>>>>> amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when they >>>>>>>>>>>>>>>>> came up with
something neat they'd leave out a vital detail in the >>>>>>>>>>>>>>>>> data sheet.
They introduced a really nice MOSFET input op-amp and >>>>>>>>>>>>>>>>> failed to mention
in the data sheet that it had about 10pF input >>>>>>>>>>>>>>>>> capacitance. For once I'd
almost got a printed circuit layout that worked first >>>>>>>>>>>>>>>>> time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback >>>>>>>>>>>>>>>>> resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated.
Regular opamps have about 1pF of input capacitance to >>>>>>>>>>>>>>> ground.
Do you use opamps with a ground pin?
Don't be silly. The ground reference is through the >>>>>>>>>>>>> negative rail
My favorite gumdrop opamp, OPA197, has a typ "common mode" >>>>>>>>>>>>>> capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386 >>>>>>>>>>>>>
It's on page 7 of the data sheet. I was more worried about the >>>>>>>>>>>>> differential capacitance, which is 1.6pF for that part (and >>>>>>>>>>>>> pretty
typical). I could try to explain the difference between >>>>>>>>>>>>> "differential"
and "common mode" but if you haven't found out about that >>>>>>>>>>>>> by now, you
clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode
capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be >>>>>>>>>>>> blamed on
differential capacitance and not care about common-mode >>>>>>>>>>>> capacitance?
As we?ve discussed before, the differential input capacitance >>>>>>>>>>> of an op amp
under bias is hard to measure, and the data sheet values are >>>>>>>>>>> unreliable.
The best way I know of is to put a very small pot directly in >>>>>>>>>>> series with
the inverting input and look at what happens to the phase >>>>>>>>>>> margin.
The CM capacitance you can get by doing the same on the >>>>>>>>>>> noninverting input
and looking at the bandwidth.˙ Feedback bootstraps out the >>>>>>>>>>> differential
capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C
between one
pin and the rails, and sometimes as the c of both pins in >>>>>>>>>> parellel to
the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, >>>>>>>>>> assumuing
the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered >>>>>>>>> off, none of
the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model >>>>>>>> converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt step, >>>>>>>> through a 1M resistor. The output is a nice exponential with tau = >>>>>>>> 6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped in a >>>>>>>> follower.
It doesn't. There's a collector/base or gate/drain capacitance
that has
to be charged up if the input moves vis-a-vis local ground (in
this case
the local rail voltages inside the chip). There are heroic
measures that
can minimise this - essentially floating the power rails though they >>>>>>> move too slowly to be of all that much help - but regular followers >>>>>>> don't use them.
Imagine three caps.
Don't bother.
<snip>
My sim measured only C2, because both C1 and C3 followed the input so >>>>>> were bootstrapped out of existence.
Whatever that is supposed to mean.
<snip>
Thanks, that makes sense, beforehand I too would have said it was
C1+C2
It's interesting, but one can just Spice actual circuits and see what
happens. Understanding the capacitances helps make the initial opamp
selections to sim.
If the simulation is any good. The published simulation models are
mostly behavioral, and precise enough for the purpose the marketing
people had in mind.
A frustrating thing is that the opamp manufacturer has an exceedingly
accurate spice model of the part that their designers created in
order to optimise and verify the design, but the company won't give
that one to the public.
It's "commercial in confidence" because it exposes a lot of the
detailed design of the chip being simulated.
The schematic in the datasheet is often drawn by marketing people who
have never discussed it with the design engineers, let alone seen the
real schematic, and is sometimes a source of great amusement to the
actual designers.
Commercial secrecy pretty much demands that.
There are several commercial lab services that will take a competitor's
chip that you obtained, (including mixed-signal designs much more complicated than an op-amp), and reverse engineer it for a smallish fee. They provide detailed schematics and layout. It is much cheaper than a
mask set and well within the means of every competitor. It isn't usually that interesting except perhaps e.g. to see whether one's patent is
being infringed.
˙˙The public spice model is quite
possibly created in a similar manner, but possibly corrected based on
some measurements by apps engineers or based on complaints from
customers. Meanwhile the really accurate model sits on some internal
server being ignored while the design engineers have moved on to some
other product.
It's not ignored - just too revealing to be made public.
Keeping the best spice models secret from customers achieves little, as
any competitor would already have full schematics if they wanted them. Perhaps the non-technical management and shareholders don't appreciate
this, or don't appreciate the significant extra value to the customer of having a simulation model that is really accurate.
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to
be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
On 2026-06-08 07:38, Chris Jones wrote:
On 8/06/2026 3:36 pm, Bill Sloman wrote:
On 8/06/2026 12:12 pm, Chris Jones wrote:
On 8/06/2026 2:04 am, john larkin wrote:
On Sun, 7 Jun 2026 14:40:04 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman >>>>>>>>>>>>>>>>> <bill.sloman@ieee.org>Regular opamps have about 1pF of input capacitance to >>>>>>>>>>>>>>>> ground.
wrote:
On 6/06/2026 10:53 pm, john larkin wrote: >>>>>>>>>>>>>>>>>>> On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet >>>>>>>>>>>>>>>>>>> <erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote: >>>>>>>>>>>>>>>>>>>>> On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY >>>>>>>>>>>>>>>>>>>>>They changed the process on a part that's 47 years >>>>>>>>>>>>>>>>>>>>> old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center >>>>>>>>>>>>>>>>>>>>> Lunatic Fringe Electronics
More than a process change, it is a whole different >>>>>>>>>>>>>>>>>>>> product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not >>>>>>>>>>>>>>>>>>>> amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when >>>>>>>>>>>>>>>>>> they came up with
something neat they'd leave out a vital detail in the >>>>>>>>>>>>>>>>>> data sheet.
They introduced a really nice MOSFET input op-amp and >>>>>>>>>>>>>>>>>> failed to mention
in the data sheet that it had about 10pF input >>>>>>>>>>>>>>>>>> capacitance. For once I'd
almost got a printed circuit layout that worked first >>>>>>>>>>>>>>>>>> time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback >>>>>>>>>>>>>>>>>> resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated. >>>>>>>>>>>>>>>>
Do you use opamps with a ground pin?
Don't be silly. The ground reference is through the >>>>>>>>>>>>>> negative rail
My favorite gumdrop opamp, OPA197, has a typ "common >>>>>>>>>>>>>>> mode" capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386 >>>>>>>>>>>>>>
It's on page 7 of the data sheet. I was more worried about >>>>>>>>>>>>>> the
differential capacitance, which is 1.6pF for that part >>>>>>>>>>>>>> (and pretty
typical). I could try to explain the difference between >>>>>>>>>>>>>> "differential"
and "common mode" but if you haven't found out about that >>>>>>>>>>>>>> by now, you
clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode >>>>>>>>>>>>> capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be >>>>>>>>>>>>> blamed on
differential capacitance and not care about common-mode >>>>>>>>>>>>> capacitance?
As we?ve discussed before, the differential input
capacitance of an op amp
under bias is hard to measure, and the data sheet values are >>>>>>>>>>>> unreliable.
The best way I know of is to put a very small pot directly >>>>>>>>>>>> in series with
the inverting input and look at what happens to the phase >>>>>>>>>>>> margin.
The CM capacitance you can get by doing the same on the >>>>>>>>>>>> noninverting input
and looking at the bandwidth.˙ Feedback bootstraps out the >>>>>>>>>>>> differential
capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C >>>>>>>>>>> between one
pin and the rails, and sometimes as the c of both pins in >>>>>>>>>>> parellel to
the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, >>>>>>>>>>> assumuing
the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered >>>>>>>>>> off, none of
the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model >>>>>>>>> converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt >>>>>>>>> step,
through a 1M resistor. The output is a nice exponential with tau = >>>>>>>>> 6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped >>>>>>>>> in a
follower.
It doesn't. There's a collector/base or gate/drain capacitance >>>>>>>> that has
to be charged up if the input moves vis-a-vis local ground (in >>>>>>>> this case
the local rail voltages inside the chip). There are heroic
measures that
can minimise this - essentially floating the power rails though >>>>>>>> they
move too slowly to be of all that much help - but regular followers >>>>>>>> don't use them.
Imagine three caps.
Don't bother.
<snip>
My sim measured only C2, because both C1 and C3 followed the
input so
were bootstrapped out of existence.
Whatever that is supposed to mean.
<snip>
Thanks, that makes sense, beforehand I too would have said it was >>>>>> C1+C2
It's interesting, but one can just Spice actual circuits and see what >>>>> happens. Understanding the capacitances helps make the initial opamp >>>>> selections to sim.
If the simulation is any good. The published simulation models are
mostly behavioral, and precise enough for the purpose the marketing
people had in mind.
A frustrating thing is that the opamp manufacturer has an
exceedingly accurate spice model of the part that their designers
created in order to optimise and verify the design, but the company
won't give that one to the public.
It's "commercial in confidence" because it exposes a lot of the
detailed design of the chip being simulated.
The schematic in the datasheet is often drawn by marketing people
who have never discussed it with the design engineers, let alone
seen the real schematic, and is sometimes a source of great
amusement to the actual designers.
Commercial secrecy pretty much demands that.
There are several commercial lab services that will take a
competitor's chip that you obtained, (including mixed-signal designs
much more complicated than an op-amp), and reverse engineer it for a
smallish fee. They provide detailed schematics and layout. It is much
cheaper than a mask set and well within the means of every competitor.
It isn't usually that interesting except perhaps e.g. to see whether
one's patent is being infringed.
˙˙The public spice model is quite
possibly created in a similar manner, but possibly corrected based
on some measurements by apps engineers or based on complaints from
customers. Meanwhile the really accurate model sits on some internal
server being ignored while the design engineers have moved on to
some other product.
It's not ignored - just too revealing to be made public.
Keeping the best spice models secret from customers achieves little,
as any competitor would already have full schematics if they wanted
them. Perhaps the non-technical management and shareholders don't
appreciate this, or don't appreciate the significant extra value to
the customer of having a simulation model that is really accurate.
If they don't own the fab, there may well be NDA restrictions on the
device models.
On 8/06/2026 9:38 pm, Chris Jones wrote:
On 8/06/2026 3:36 pm, Bill Sloman wrote:
On 8/06/2026 12:12 pm, Chris Jones wrote:
On 8/06/2026 2:04 am, john larkin wrote:
On Sun, 7 Jun 2026 14:40:04 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman >>>>>>>>>>>>>>>>> <bill.sloman@ieee.org>Regular opamps have about 1pF of input capacitance to >>>>>>>>>>>>>>>> ground.
wrote:
On 6/06/2026 10:53 pm, john larkin wrote: >>>>>>>>>>>>>>>>>>> On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet >>>>>>>>>>>>>>>>>>> <erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote: >>>>>>>>>>>>>>>>>>>>> On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY >>>>>>>>>>>>>>>>>>>>>They changed the process on a part that's 47 years >>>>>>>>>>>>>>>>>>>>> old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center >>>>>>>>>>>>>>>>>>>>> Lunatic Fringe Electronics
More than a process change, it is a whole different >>>>>>>>>>>>>>>>>>>> product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not >>>>>>>>>>>>>>>>>>>> amend the part number
in any way.
You'd better not buy TI parts any more.
They were rarely anybody's first choice. Even when >>>>>>>>>>>>>>>>>> they came up with
something neat they'd leave out a vital detail in the >>>>>>>>>>>>>>>>>> data sheet.
They introduced a really nice MOSFET input op-amp and >>>>>>>>>>>>>>>>>> failed to mention
in the data sheet that it had about 10pF input >>>>>>>>>>>>>>>>>> capacitance. For once I'd
almost got a printed circuit layout that worked first >>>>>>>>>>>>>>>>>> time, but I had to
bodge in 2.2pF capacitor in parallel with the feedback >>>>>>>>>>>>>>>>>> resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated. >>>>>>>>>>>>>>>>
Do you use opamps with a ground pin?
Don't be silly. The ground reference is through the >>>>>>>>>>>>>> negative rail
My favorite gumdrop opamp, OPA197, has a typ "common >>>>>>>>>>>>>>> mode" capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386 >>>>>>>>>>>>>>
It's on page 7 of the data sheet. I was more worried about >>>>>>>>>>>>>> the
differential capacitance, which is 1.6pF for that part >>>>>>>>>>>>>> (and pretty
typical). I could try to explain the difference between >>>>>>>>>>>>>> "differential"
and "common mode" but if you haven't found out about that >>>>>>>>>>>>>> by now, you
clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode >>>>>>>>>>>>> capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be >>>>>>>>>>>>> blamed on
differential capacitance and not care about common-mode >>>>>>>>>>>>> capacitance?
As we?ve discussed before, the differential input
capacitance of an op amp
under bias is hard to measure, and the data sheet values are >>>>>>>>>>>> unreliable.
The best way I know of is to put a very small pot directly >>>>>>>>>>>> in series with
the inverting input and look at what happens to the phase >>>>>>>>>>>> margin.
The CM capacitance you can get by doing the same on the >>>>>>>>>>>> noninverting input
and looking at the bandwidth.˙ Feedback bootstraps out the >>>>>>>>>>>> differential
capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C >>>>>>>>>>> between one
pin and the rails, and sometimes as the c of both pins in >>>>>>>>>>> parellel to
the world.
A diagram of the several caps, with values, would help.
One can Spice a standard inverting amp and see what it does, >>>>>>>>>>> assumuing
the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered >>>>>>>>>> off, none of
the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model >>>>>>>>> converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt >>>>>>>>> step,
through a 1M resistor. The output is a nice exponential with tau = >>>>>>>>> 6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped >>>>>>>>> in a
follower.
It doesn't. There's a collector/base or gate/drain capacitance >>>>>>>> that has
to be charged up if the input moves vis-a-vis local ground (in >>>>>>>> this case
the local rail voltages inside the chip). There are heroic
measures that
can minimise this - essentially floating the power rails though >>>>>>>> they
move too slowly to be of all that much help - but regular followers >>>>>>>> don't use them.
Imagine three caps.
Don't bother.
<snip>
My sim measured only C2, because both C1 and C3 followed the
input so
were bootstrapped out of existence.
Whatever that is supposed to mean.
<snip>
Thanks, that makes sense, beforehand I too would have said it was >>>>>> C1+C2
It's interesting, but one can just Spice actual circuits and see what >>>>> happens. Understanding the capacitances helps make the initial opamp >>>>> selections to sim.
If the simulation is any good. The published simulation models are
mostly behavioral, and precise enough for the purpose the marketing
people had in mind.
A frustrating thing is that the opamp manufacturer has an
exceedingly accurate spice model of the part that their designers
created in order to optimise and verify the design, but the company
won't give that one to the public.
It's "commercial in confidence" because it exposes a lot of the
detailed design of the chip being simulated.
The schematic in the datasheet is often drawn by marketing people
who have never discussed it with the design engineers, let alone
seen the real schematic, and is sometimes a source of great
amusement to the actual designers.
Commercial secrecy pretty much demands that.
There are several commercial lab services that will take a
competitor's chip that you obtained, (including mixed-signal designs
much more complicated than an op-amp), and reverse engineer it for a
smallish fee. They provide detailed schematics and layout. It is much
cheaper than a mask set and well within the means of every competitor.
It isn't usually that interesting except perhaps e.g. to see whether
one's patent is being infringed.
A smallish fee isn't going to be all that small.
˙˙The public spice model is quite
possibly created in a similar manner, but possibly corrected based
on some measurements by apps engineers or based on complaints from
customers. Meanwhile the really accurate model sits on some internal
server being ignored while the design engineers have moved on to
some other product.
It's not ignored - just too revealing to be made public.
Keeping the best spice models secret from customers achieves little,
as any competitor would already have full schematics if they wanted them.
If they wanted them badly enough. Reverse engineering may not be as expensive as a complete mask set, but it is quite expensive, and keeps fairly skilled people from your own firm busy for quite a while.
I worked o voltage contrast for a bit, and the kind of electron
microscope that can see what's going on on the exposed surface of an ude-encapsulated chip isn't cheap.
Perhaps the non-technical management and shareholders don't appreciate
this, or don't appreciate the significant extra value to the customer
of having a simulation model that is really accurate.
And really slow? Behavioral model are not only less revealing than transistor level models, but run a lot faster.
On 8/06/2026 11:31 pm, Bill Sloman wrote:
On 8/06/2026 9:38 pm, Chris Jones wrote:
On 8/06/2026 3:36 pm, Bill Sloman wrote:
On 8/06/2026 12:12 pm, Chris Jones wrote:
On 8/06/2026 2:04 am, john larkin wrote:
On Sun, 7 Jun 2026 14:40:04 -0000 (UTC), piglet
<erichpwagner@hotmail.com> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 14:45:40 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 11:44 am, john larkin wrote:
On Sun, 7 Jun 2026 00:31:01 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sat, 6 Jun 2026 20:41:07 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Sun, 7 Jun 2026 03:06:10 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 7/06/2026 2:33 am, john larkin wrote:
On Sun, 7 Jun 2026 02:19:03 +1000, Bill Sloman >>>>>>>>>>>>>>>> <bill.sloman@ieee.org>
wrote:
On 7/06/2026 1:57 am, john larkin wrote:
On Sun, 7 Jun 2026 01:10:57 +1000, Bill Sloman >>>>>>>>>>>>>>>>>> <bill.sloman@ieee.org>Regular opamps have about 1pF of input capacitance to >>>>>>>>>>>>>>>>> ground.
wrote:
On 6/06/2026 10:53 pm, john larkin wrote: >>>>>>>>>>>>>>>>>>>> On Sat, 6 Jun 2026 11:29:35 -0000 (UTC), piglet >>>>>>>>>>>>>>>>>>>> <erichpwagner@hotmail.com> wrote:
They were rarely anybody's first choice. Even when >>>>>>>>>>>>>>>>>>> they came up with
john larkin <jl@glen--canyon.com> wrote: >>>>>>>>>>>>>>>>>>>>>> On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones >>>>>>>>>>>>>>>>>>>>>> <lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY >>>>>>>>>>>>>>>>>>>>>>They changed the process on a part that's 47 years >>>>>>>>>>>>>>>>>>>>>> old.
Scandalous.
John Larkin
Highland Tech Glen Canyon Design Center >>>>>>>>>>>>>>>>>>>>>> Lunatic Fringe Electronics
More than a process change, it is a whole different >>>>>>>>>>>>>>>>>>>>> product. Old was NPN
input stage, new is PNP inputs. Unforgivable to not >>>>>>>>>>>>>>>>>>>>> amend the part number
in any way.
You'd better not buy TI parts any more. >>>>>>>>>>>>>>>>>>>
something neat they'd leave out a vital detail in the >>>>>>>>>>>>>>>>>>> data sheet.
They introduced a really nice MOSFET input op-amp and >>>>>>>>>>>>>>>>>>> failed to mention
in the data sheet that it had about 10pF input >>>>>>>>>>>>>>>>>>> capacitance. For once I'd
almost got a printed circuit layout that worked first >>>>>>>>>>>>>>>>>>> time, but I had to
bodge in 2.2pF capacitor in parallel with the >>>>>>>>>>>>>>>>>>> feedback resistor to kill
the oscillation the 10pF produced.
Yeah, sometimes electronics gets complicated. >>>>>>>>>>>>>>>>>
Do you use opamps with a ground pin?
Don't be silly. The ground reference is through the >>>>>>>>>>>>>>> negative rail
My favorite gumdrop opamp, OPA197, has a typ "common >>>>>>>>>>>>>>>> mode" capacitance
of 6.4 pF, whatever that means.
https://www.ti.com/lit/ds/symlink/opa197.pdf?ts=1780716494386 >>>>>>>>>>>>>>>
It's on page 7 of the data sheet. I was more worried >>>>>>>>>>>>>>> about the
differential capacitance, which is 1.6pF for that part >>>>>>>>>>>>>>> (and pretty
typical). I could try to explain the difference between >>>>>>>>>>>>>>> "differential"
and "common mode" but if you haven't found out about that >>>>>>>>>>>>>>> by now, you
clearly aren't interested in finding out.
Explain it to me. I'm not sure what the commmon-mode >>>>>>>>>>>>>> capacitance of an
opamp is.
Any explaination why the peaking in your circuit could be >>>>>>>>>>>>>> blamed on
differential capacitance and not care about common-mode >>>>>>>>>>>>>> capacitance?
As we?ve discussed before, the differential input
capacitance of an op amp
under bias is hard to measure, and the data sheet values >>>>>>>>>>>>> are unreliable.
The best way I know of is to put a very small pot directly >>>>>>>>>>>>> in series with
the inverting input and look at what happens to the phase >>>>>>>>>>>>> margin.
The CM capacitance you can get by doing the same on the >>>>>>>>>>>>> noninverting input
and looking at the bandwidth.˙ Feedback bootstraps out the >>>>>>>>>>>>> differential
capacitance at low frequency.
Cheers
Phil Hobbs
I've seen the "common mode" capacitance defined as the C >>>>>>>>>>>> between one
pin and the rails, and sometimes as the c of both pins in >>>>>>>>>>>> parellel to
the world.
A diagram of the several caps, with values, would help. >>>>>>>>>>>>
One can Spice a standard inverting amp and see what it does, >>>>>>>>>>>> assumuing
the Spice model is accurate.
It?s the measurement that?s difficult?if the amp is powered >>>>>>>>>>> off, none of
the junction capacitances will be right.
Cheers
Phil Hobbs
I have a Spice model of the OPA197, basically TI's Pspice model >>>>>>>>>> converted for LT Spice.
I made a unity-gain follower sim and drove that with a 1 volt >>>>>>>>>> step,
through a 1M resistor. The output is a nice exponential with >>>>>>>>>> tau =
6.45 usec, which means the c to ground is 6.45 pF.
The TI data sheet says that cm capacitance is 6.4!
The differential input c disappeared because it's bootstrapped >>>>>>>>>> in a
follower.
It doesn't. There's a collector/base or gate/drain capacitance >>>>>>>>> that has
to be charged up if the input moves vis-a-vis local ground (in >>>>>>>>> this case
the local rail voltages inside the chip). There are heroic
measures that
can minimise this - essentially floating the power rails though >>>>>>>>> they
move too slowly to be of all that much help - but regular
followers
don't use them.
Imagine three caps.
Don't bother.
<snip>
My sim measured only C2, because both C1 and C3 followed the
input so
were bootstrapped out of existence.
Whatever that is supposed to mean.
<snip>
Thanks, that makes sense, beforehand I too would have said it was >>>>>>> C1+C2
It's interesting, but one can just Spice actual circuits and see what >>>>>> happens. Understanding the capacitances helps make the initial opamp >>>>>> selections to sim.
If the simulation is any good. The published simulation models are
mostly behavioral, and precise enough for the purpose the marketing
people had in mind.
A frustrating thing is that the opamp manufacturer has an
exceedingly accurate spice model of the part that their designers
created in order to optimise and verify the design, but the company >>>>> won't give that one to the public.
It's "commercial in confidence" because it exposes a lot of the
detailed design of the chip being simulated.
The schematic in the datasheet is often drawn by marketing people
who have never discussed it with the design engineers, let alone
seen the real schematic, and is sometimes a source of great
amusement to the actual designers.
Commercial secrecy pretty much demands that.
There are several commercial lab services that will take a
competitor's chip that you obtained, (including mixed-signal designs
much more complicated than an op-amp), and reverse engineer it for a
smallish fee. They provide detailed schematics and layout. It is much
cheaper than a mask set and well within the means of every
competitor. It isn't usually that interesting except perhaps e.g. to
see whether one's patent is being infringed.
A smallish fee isn't going to be all that small.
The person who arranged it said it was a few thousand. A mask set is
maybe a hundred times that.
˙˙The public spice model is quite
possibly created in a similar manner, but possibly corrected based
on some measurements by apps engineers or based on complaints from
customers. Meanwhile the really accurate model sits on some
internal server being ignored while the design engineers have moved >>>>> on to some other product.
It's not ignored - just too revealing to be made public.
Keeping the best spice models secret from customers achieves little,
as any competitor would already have full schematics if they wanted
them.
If they wanted them badly enough. Reverse engineering may not be as
expensive as a complete mask set, but it is quite expensive, and keeps
fairly skilled people from your own firm busy for quite a while.
No, just pay someone to do it. But, it's not all that useful if you
intend to make something much better than what your competitors already make.
I worked o voltage contrast for a bit, and the kind of electron
microscope that can see what's going on on the exposed surface of an
de-encapsulated chip isn't cheap.
I think at least some of those reverse engineering companies are run out
of university labs. They already have the equipment and it's not always busy. The service I know of did not operate the chip, they just took
images and made netlists / schematics, and measured the process parameters.
Perhaps the non-technical management and shareholders don't
appreciate this, or don't appreciate the significant extra value to
the customer of having a simulation model that is really accurate.
And really slow? Behavioral model are not only less revealing than
transistor level models, but run a lot faster.
It is good to have both.
My block on one chip simulated 1e12 times
slower than real time, but that had many thousands of transistors in it,
and computers have got faster over the 20 years since then.
I did have
to simulate the whole real circuit for one beat period of a two-tone distortion test, and running all the process corners and temperatures
did take many days, but I also made a fast behavioural model to make
sure that the digital state machine could calibrate the analogue part properly etc.
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to
be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world. >>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
Thanks,
Joe
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>> be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
Thanks,
Joe
Good grief, just google
bat echolocation nanosecond
The history of science is rich with people saying "that's not
possible" when it turns out to be.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
Thanks,
Joe
Good grief, just google
bat echolocation nanosecond
The history of science is rich with people saying "that's not
possible" when it turns out to be.
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I
certainly would have when crappy compressed MP3s took over the world. >>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>> be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
Thanks,
Joe
Good grief, just google
bat echolocation nanosecond
The history of science is rich with people saying "that's not
possible" when it turns out to be.
"Bat sonar: an alternative interpretation of the 10-ns jitter result" <https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution
hitherto unknown in any animal, namely a 10-ns jitter detection
threshold in echolocating bats."
john larkin <jl@glen--canyon.com>wrote:
Good grief, just google
bat echolocation nanosecond
The history of science is rich with people saying "that's not
possible" when it turns out to be.
john larkin <jl@glen--canyon.com>wrote:
Good grief, just google
bat echolocation nanosecond
The history of science is rich with people saying "that's not
possible" when it turns out to be.
FYI:
Speed of sound is 340.29 m / s
In a nano-second sound moves:
340.29 * 10^-9 = 3.4029e-07 meter
or 3.4029e-07 * 1000 = 0.00034029 milimeter
Even a 1 degree phase shift is 1/360 so about 0.000001 mm,
distance between 2 neurons.. hairs in the ear?
Not even counting <MAKING the sound.
Beep!
You can express Any Sing in nano seconds
!!!
BTW the signal from the nerves in the ear to the brain takes orders of magnitude more time
Drop your nano nano obsession!!!
Did you not got hit by crocodile sounds once?
There is a survival series here on TV every sunday .. those guys catch alligators with a hook and same bait.
I now know how to catch and kill an alligator!
Done ANYTHING with sound ever?
john larkin <jl@glen--canyon.com>wrote:
On Wed, 10 Jun 2026 06:22:58 GMT, Jan Panteltje <alien@comet.invalid>wrote:
john larkin <jl@glen--canyon.com>wrote:
Good grief, just google
bat echolocation nanosecond
The history of science is rich with people saying "that's not
possible" when it turns out to be.
FYI:
Speed of sound is 340.29 m / s
In a nano-second sound moves:
340.29 * 10^-9 = 3.4029e-07 meter
or 3.4029e-07 * 1000 = 0.00034029 milimeter
Even a 1 degree phase shift is 1/360 so about 0.000001 mm,
distance between 2 neurons.. hairs in the ear?
Not even counting <MAKING the sound.
Beep!
You can express Any Sing in nano seconds
!!!
I use nanoseconds (or pico of femto) to describe anything below a >microsecond. I do have old books that use millimicrosecond units, or >micromicrofarad, uuF.
BTW the signal from the nerves in the ear to the brain takes orders of magnitude more time
The prop delay between your wrist and your brain obviously makes it >impossible to play tennis.
My favorite expert-impossible was fathead boffins declaring that a
biological rotating motor was impossible. I think there is one that
runs something like 100K RPM. We would not have babies without a
spinning molecular machine.
Drop your nano nano obsession!!!
Did you not got hit by crocodile sounds once?
We helped discover some infrasonic croc calls, yes.
There is a survival series here on TV every sunday .. those guys catch alligators with a hook and same bait.
I now know how to catch and kill an alligator!
Done ANYTHING with sound ever?
I designed a guitar amp once, the Ryder 200 or 500 or something. Named
after a buddy, Frank Ryder. He wised up and married a rich German
girl and got out of audio.
And of course I designed the things that found the alligator calls in >Mississippi.
Oh, and the paging system for the New York City subway. Not very
hi-fi.
I don't like music and audio is boring and low profit, so I prefer
picosecond stuff.
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>> be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
"The transfer function of a target limits the jitter detection
threshold with signals of echolocating FM-bats" <https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are
able to discriminate alternations in delay down to 10 ns, which
appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result" <https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution
hitherto unknown in any animal, namely a 10-ns jitter detection
threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity: <https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
On 2026-06-09 19:15, Jeff Liebermann wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>> be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
"The transfer function of a target limits the jitter detection
threshold with signals of echolocating FM-bats"
<https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are
able to discriminate alternations in delay down to 10 ns, which
appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result"
<https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution
hitherto unknown in any animal, namely a 10-ns jitter detection
threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity:
<https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
In my neck of the woods, when you rhetorically quote some spec in the >100-999 nm range, you normally call it "submicron", whereas anything
between 1 nm and 100 nm is "nanometer".
Cheers
Phil Hobbs
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
"The transfer function of a target limits the jitter detection
threshold with signals of echolocating FM-bats" ><https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are
able to discriminate alternations in delay down to 10 ns, which
appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result" ><https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution
hitherto unknown in any animal, namely a 10-ns jitter detection
threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity: ><https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>>be close to particularly good brains.
I read a study that says that bats can correlate time between their >>>>ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
"The transfer function of a target limits the jitter detection
threshold with signals of echolocating FM-bats" >><https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are
able to discriminate alternations in delay down to 10 ns, which
appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result" >><https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution
hitherto unknown in any animal, namely a 10-ns jitter detection
threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity: >><https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
So that's a source of the 10ns stuff. The theory is that there was an >instrumentation error, which is certainly plausible as no biological
system is that fast, so biological researchers are far out of their
domain for sure.
Joe
PS: The 100,000 rpm spinner in biology is "ATP Synthase", the enzyme
system that converts between ADP and ATP in the mitochondria (in
animals) and chloroplasts (in plants).
.<https://en.wikipedia.org/wiki/ATP_synthase>
JMG
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>>be close to particularly good brains.
I read a study that says that bats can correlate time between their >>>>ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
"The transfer function of a target limits the jitter detection
threshold with signals of echolocating FM-bats" >><https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are
able to discriminate alternations in delay down to 10 ns, which
appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result" >><https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution
hitherto unknown in any animal, namely a 10-ns jitter detection
threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity: >><https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
So that's a source of the 10ns stuff. The theory is that there was an >instrumentation error, which is certainly plausible as no biological
system is that fast, so biological researchers are far out of their
domain for sure.
Joe
PS: The 100,000 rpm spinner in biology is "ATP Synthase", the enzyme
system that converts between ADP and ATP in the mitochondria (in
animals) and chloroplasts (in plants).
.<https://en.wikipedia.org/wiki/ATP_synthase>
JMG
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info >>>>>>>>> on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick >>>>>>>>> this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI >>>>>>>>> never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>>> be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
"The transfer function of a target limits the jitter detection
threshold with signals of echolocating FM-bats"
<https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are
able to discriminate alternations in delay down to 10 ns, which
appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result"
<https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution
hitherto unknown in any animal, namely a 10-ns jitter detection
threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity:
<https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
So that's a source of the 10ns stuff. The theory is that there was an
instrumentation error, which is certainly plausible as no biological
system is that fast, so biological researchers are far out of their
domain for sure.
Why do you say that no biological system can be that fast?
Anything less than a microsecond is astounding, inside the gooey head
of a bat flapping its wings mid-air hunting a moth.
PS: The 100,000 rpm spinner in biology is "ATP Synthase", the enzyme
system that converts between ADP and ATP in the mitochondria (in
animals) and chloroplasts (in plants).
.<https://en.wikipedia.org/wiki/ATP_synthase>
DNA helicase, the little gadget that splits our DNA when a cell
divides, spins at about 10,000 RPM.
<Rotating biological motors were declared to be impossible, and
rotating flagellum were known to be optical illusions.> Once.
Google the <> above.
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info >>>>>>>>> on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick >>>>>>>>> this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI >>>>>>>>> never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>>>be close to particularly good brains.
I read a study that says that bats can correlate time between their >>>>>ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
"The transfer function of a target limits the jitter detection
threshold with signals of echolocating FM-bats" >>><https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are
able to discriminate alternations in delay down to 10 ns, which
appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result" >>><https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution
hitherto unknown in any animal, namely a 10-ns jitter detection
threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity: >>><https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
So that's a source of the 10ns stuff. The theory is that there was an >>instrumentation error, which is certainly plausible as no biological
system is that fast, so biological researchers are far out of their
domain for sure.
It's only my best guess(tm). I didn't have much success at finding
the oldest bat related citation that included a 10 nsec response time.
Joe
PS: The 100,000 rpm spinner in biology is "ATP Synthase", the enzyme >>system that converts between ADP and ATP in the mitochondria (in
animals) and chloroplasts (in plants).
.<https://en.wikipedia.org/wiki/ATP_synthase>
JMG
Sigh. I initially mentioned that there might have been some confusion >between response time and jitter. Now, you add DNA replication to the >confusion. Time for a sanity check.
What got my attention was the radical difference between the alleged
10 nsec nervous response time in bats, and the much slower nerve
conduction times in humans. (I couldn't find specific numbers for
bats).
"Nerve conduction velocity" ><https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to
over 120 m/s".
I once watched a "cloud" of fruit bats emerging from the trees at
dusk:
<https://en.wikipedia.org/wiki/Egyptian_fruit_bat>
I don't know how many there were, but my guess(tm) is in the
thousands. The bats were not using their sonar for locating moths.
Instead, they were looking for fruit and using their sonar to prevent
mid-air collisions. I watched carefully and didn't see any collisions
or bats falling from the sky. In order to do that, the muscles that
move the bats wings need to quickly respond to brain signals and the
muscles need to move quite fast. 10 nsec response time isn't going to
work when the signals move at 0.5 m/s to over 120 m/s. A nerve
impulse moves at perhaps 1 meter/sec (or 10 nanometers in 10
nanoseconds). A 10 nsec nerve impulse will have moved a microscopic >distance.
On Wed, 10 Jun 2026 19:32:15 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>> wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>> wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
Sigh. I initially mentioned that there might have been some confusion
between response time and jitter. Now, you add DNA replication to the
confusion. Time for a sanity check.
What got my attention was the radical difference between the alleged
10 nsec nervous response time in bats, and the much slower nerve
conduction times in humans. (I couldn't find specific numbers for
bats).
"Nerve conduction velocity"
<https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to
over 120 m/s".
I once watched a "cloud" of fruit bats emerging from the trees at
dusk:
<https://en.wikipedia.org/wiki/Egyptian_fruit_bat>
I don't know how many there were, but my guess(tm) is in the
thousands. The bats were not using their sonar for locating moths.
Instead, they were looking for fruit and using their sonar to prevent
mid-air collisions. I watched carefully and didn't see any collisions
or bats falling from the sky. In order to do that, the muscles that
move the bats wings need to quickly respond to brain signals and the
muscles need to move quite fast. 10 nsec response time isn't going to
work when the signals move at 0.5 m/s to over 120 m/s. A nerve
impulse moves at perhaps 1 meter/sec (or 10 nanometers in 10
nanoseconds). A 10 nsec nerve impulse will have moved a microscopic
distance.
For the record, I said "nanosecond resolution" not 10 nanoseconds.
And yes, nerve impulses are assumed move about a meter per second, yet
people play table tennis.
One possible explanation is that nerve impulses don't move meters per
second.
Bill Sloman <bill.sloman@ieee.org>wrote:
On 11/06/2026 3:29 pm, john larkin wrote:
On Wed, 10 Jun 2026 19:32:15 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>> wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>>> wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>> wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
<snip>
Sigh. I initially mentioned that there might have been some confusion
between response time and jitter. Now, you add DNA replication to the
confusion. Time for a sanity check.
What got my attention was the radical difference between the alleged
10 nsec nervous response time in bats, and the much slower nerve
conduction times in humans. (I couldn't find specific numbers for
bats).
"Nerve conduction velocity"
<https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to
over 120 m/s".
I once watched a "cloud" of fruit bats emerging from the trees at
dusk:
<https://en.wikipedia.org/wiki/Egyptian_fruit_bat>
I don't know how many there were, but my guess(tm) is in the
thousands. The bats were not using their sonar for locating moths.
Instead, they were looking for fruit and using their sonar to prevent
mid-air collisions. I watched carefully and didn't see any collisions
or bats falling from the sky. In order to do that, the muscles that
move the bats wings need to quickly respond to brain signals and the
muscles need to move quite fast. 10 nsec response time isn't going to
work when the signals move at 0.5 m/s to over 120 m/s. A nerve
impulse moves at perhaps 1 meter/sec (or 10 nanometers in 10
nanoseconds). A 10 nsec nerve impulse will have moved a microscopic
distance.
For the record, I said "nanosecond resolution" not 10 nanoseconds.
But it is still nonsense.
And yes, nerve impulses are assumed move about a meter per second, yet
people play table tennis.
One possible explanation is that nerve impulses don't move meters per
second.
Possible, but not plausible. People have been measuring nerve impulse
speed for quite a while now.
https://en.wikipedia.org/wiki/Squid_giant_axon
There was quite a lot of fuss about that measurement back in 1952 and it >lead to a Nobel Prize - I remember it and I was only a kid at the time.
https://en.wikipedia.org/wiki/Nerve_conduction_velocity
cites work going as far back as 1972. Some of speeds cited get up to 120 >meters per second. A lot faster than your "meter per second" but not
fast enough for 10nsec resolution to be plausible.
16 * 365 * 24 * 60 * 60 * 10^9 = 5.04576e+17 nano nanos
Anything less than a microsecond is astounding, inside the gooey head
of a bat flapping its wings mid-air hunting a moth.
Some [nerve impulse] speeds cited get up to 120
meters per second. A lot faster than your "meter per second" but not
fast enough for 10nsec resolution to be plausible.
On 11/06/2026 3:29 pm, john larkin wrote:
On Wed, 10 Jun 2026 19:32:15 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>> wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>>> wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>> wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
<snip>
Sigh. I initially mentioned that there might have been some confusion
between response time and jitter. Now, you add DNA replication to the
confusion. Time for a sanity check.
What got my attention was the radical difference between the alleged
10 nsec nervous response time in bats, and the much slower nerve
conduction times in humans. (I couldn't find specific numbers for
bats).
"Nerve conduction velocity"
<https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to
over 120 m/s".
I once watched a "cloud" of fruit bats emerging from the trees at
dusk:
<https://en.wikipedia.org/wiki/Egyptian_fruit_bat>
I don't know how many there were, but my guess(tm) is in the
thousands. The bats were not using their sonar for locating moths.
Instead, they were looking for fruit and using their sonar to prevent
mid-air collisions. I watched carefully and didn't see any collisions
or bats falling from the sky. In order to do that, the muscles that
move the bats wings need to quickly respond to brain signals and the
muscles need to move quite fast. 10 nsec response time isn't going to
work when the signals move at 0.5 m/s to over 120 m/s. A nerve
impulse moves at perhaps 1 meter/sec (or 10 nanometers in 10
nanoseconds). A 10 nsec nerve impulse will have moved a microscopic
distance.
For the record, I said "nanosecond resolution" not 10 nanoseconds.
But it is still nonsense.
And yes, nerve impulses are assumed move about a meter per second, yet
people play table tennis.
One possible explanation is that nerve impulses don't move meters per
second.
Possible, but not plausible. People have been measuring nerve impulse
speed for quite a while now.
https://en.wikipedia.org/wiki/Squid_giant_axon
There was quite a lot of fuss about that measurement back in 1952 and it >lead to a Nobel Prize - I remember it and I was only a kid at the time.
https://en.wikipedia.org/wiki/Nerve_conduction_velocity
cites work going as far back as 1972. Some of speeds cited get up to 120 >meters per second. A lot faster than your "meter per second" but not
fast enough for 10nsec resolution to be plausible.
john larkin <jl@glen--canyon.com> wrote:
Anything less than a microsecond is astounding, inside the gooey head
of a bat flapping its wings mid-air hunting a moth.
To put it in perspective, a microsecond at the velocity of sound in air >corresponds to 0.25mm (or 0.125mm for echolocation distance
measurement).
On Thu, 11 Jun 2026 17:13:17 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 11/06/2026 3:29 pm, john larkin wrote:
On Wed, 10 Jun 2026 19:32:15 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>>> wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>>>> wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>> wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>>>>>>>>> legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
<snip>
Sigh. I initially mentioned that there might have been some confusion >>>> between response time and jitter. Now, you add DNA replication to the >>>> confusion. Time for a sanity check.
What got my attention was the radical difference between the alleged
10 nsec nervous response time in bats, and the much slower nerve
conduction times in humans. (I couldn't find specific numbers for
bats).
"Nerve conduction velocity"
<https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to
over 120 m/s".
I once watched a "cloud" of fruit bats emerging from the trees at
dusk:
<https://en.wikipedia.org/wiki/Egyptian_fruit_bat>
I don't know how many there were, but my guess(tm) is in the
thousands. The bats were not using their sonar for locating moths.
Instead, they were looking for fruit and using their sonar to prevent
mid-air collisions. I watched carefully and didn't see any collisions >>>> or bats falling from the sky. In order to do that, the muscles that
move the bats wings need to quickly respond to brain signals and the
muscles need to move quite fast. 10 nsec response time isn't going to >>>> work when the signals move at 0.5 m/s to over 120 m/s. A nerve
impulse moves at perhaps 1 meter/sec (or 10 nanometers in 10
nanoseconds). A 10 nsec nerve impulse will have moved a microscopic
distance.
For the record, I said "nanosecond resolution" not 10 nanoseconds.
But it is still nonsense.
And yes, nerve impulses are assumed move about a meter per second, yet
people play table tennis.
One possible explanation is that nerve impulses don't move meters per
second.
Possible, but not plausible. People have been measuring nerve impulse
speed for quite a while now.
They measure what's easy to measure, an electrical impulse. Maybe
that's not the information being sent.
https://en.wikipedia.org/wiki/Squid_giant_axon
There was quite a lot of fuss about that measurement back in 1952 and it
lead to a Nobel Prize - I remember it and I was only a kid at the time.
https://en.wikipedia.org/wiki/Nerve_conduction_velocity
cites work going as far back as 1972. Some of speeds cited get up to 120
meters per second. A lot faster than your "meter per second" but not
fast enough for 10nsec resolution to be plausible.
Bats catch moths. Baseballs get hit.
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
Anything less than a microsecond is astounding, inside the gooey head
of a bat flapping its wings mid-air hunting a moth.
To put it in perspective, a microsecond at the velocity of sound in air
corresponds to 0.25mm (or 0.125mm for echolocation distance
measurement).
If nerve impulses travel 100 m/s and a bat's ears are 2 cm apart, the
neural delay between ears is 200 us. And that's modulated by movement, heartbeats, things like that.
Maybe nature doesn't care about our opinions of how it's allowed to
work.
On Wed, 10 Jun 2026 19:32:15 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>>wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info >>>>>>>>>> on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick >>>>>>>>>> this up in time to remove the TI part number from your list >>>>>>>>>> of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI >>>>>>>>>> never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>>>>be close to particularly good brains.
I read a study that says that bats can correlate time between their >>>>>>ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find >>>>>that study?
"The transfer function of a target limits the jitter detection >>>>threshold with signals of echolocating FM-bats" >>>><https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are
able to discriminate alternations in delay down to 10 ns, which
appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result" >>>><https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution
hitherto unknown in any animal, namely a 10-ns jitter detection >>>>threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity: >>>><https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
So that's a source of the 10ns stuff. The theory is that there was an >>>instrumentation error, which is certainly plausible as no biological >>>system is that fast, so biological researchers are far out of their >>>domain for sure.
It's only my best guess(tm). I didn't have much success at finding
the oldest bat related citation that included a 10 nsec response time.
Joe
PS: The 100,000 rpm spinner in biology is "ATP Synthase", the enzyme >>>system that converts between ADP and ATP in the mitochondria (in
animals) and chloroplasts (in plants).
.<https://en.wikipedia.org/wiki/ATP_synthase>
JMG
Sigh. I initially mentioned that there might have been some confusion >>between response time and jitter. Now, you add DNA replication to the >>confusion. Time for a sanity check.
What got my attention was the radical difference between the alleged
10 nsec nervous response time in bats, and the much slower nerve
conduction times in humans. (I couldn't find specific numbers for
bats).
"Nerve conduction velocity" >><https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to
over 120 m/s".
I once watched a "cloud" of fruit bats emerging from the trees at
dusk:
<https://en.wikipedia.org/wiki/Egyptian_fruit_bat>
I don't know how many there were, but my guess(tm) is in the
thousands. The bats were not using their sonar for locating moths. >>Instead, they were looking for fruit and using their sonar to prevent >>mid-air collisions. I watched carefully and didn't see any collisions
or bats falling from the sky. In order to do that, the muscles that
move the bats wings need to quickly respond to brain signals and the >>muscles need to move quite fast. 10 nsec response time isn't going to
work when the signals move at 0.5 m/s to over 120 m/s. A nerve
impulse moves at perhaps 1 meter/sec (or 10 nanometers in 10
nanoseconds). A 10 nsec nerve impulse will have moved a microscopic >>distance.
For the record, I said "nanosecond resolution" not 10 nanoseconds.
And yes, nerve impulses are assumed move about a meter per second, yet
people play table tennis.
One possible explanation is that nerve impulses don't move meters per
second.
On Wed, 10 Jun 2026 22:29:45 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Wed, 10 Jun 2026 19:32:15 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>> wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>>> wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>> wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
And yes, nerve impulses are assumed move about a meter per second, yet
people play table tennis.
One possible explanation is that nerve impulses don't move meters per
second.
Methinks the mechanism might be similar to measuring the speed of
electrons in wires. Energy transmission in a wire moves at near light
speed. Electron drift velocity in wires (the movement of individual electrons) is about 1 mm/sec, which is much slower. I suspected that
nerve impulse transmission in bats might be similar. However, my
analogy breaks down because nerve impulse velocity can be 1 to 100 meters/sec, which is still much slower than near light speed (3*10^8 meters/sec).
"Nerve conduction velocity" <https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to
over 120 m/s"
"Bats are surprisingly fast decision makers" <https://www.sdu.dk/en/om-sdu/fakulteterne/naturvidenskab/nyheder-2015/2015_03_18_bat_decision>
"Sometimes we also see reaction times of only 20 milliseconds in bats,
for instance in response to loud sounds, but that is a simple reflex
reaction that does not require brain work".
20 msec response time isn't light speed it's a long way from 10 nsec.
If the flying bat is on auto-pilot, then it's making 50 course
corrections every second. Offhand, methinks that might be sufficient
to avoid mid-air collisions with other bats. Even if 10 nsec
resolution were possible, it would be overkill for a bat.
On 10/06/2026 2:44 am, john larkin wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info
on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick
this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI
never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>> be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
Thanks,
Joe
Good grief, just google
bat echolocation nanosecond
You made the claim, you do the googling.
On 12/06/2026 12:21 am, john larkin wrote:
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
Anything less than a microsecond is astounding, inside the gooey head
of a bat flapping its wings mid-air hunting a moth.
To put it in perspective, a microsecond at the velocity of sound in air >>> corresponds to 0.25mm (or 0.125mm for echolocation distance
measurement).
If nerve impulses travel 100 m/s and a bat's ears are 2 cm apart, the
neural delay between ears is 200 us. And that's modulated by movement,
heartbeats, things like that.
Maybe nature doesn't care about our opinions of how it's allowed to
work.
Obviously it doesn't. That doesn't excuse you from picking up
particularly half-baked ideas about how well it might be performing and >posting them here.
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info >>>>>>>>> on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick >>>>>>>>> this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI >>>>>>>>> never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>>>be close to particularly good brains.
I read a study that says that bats can correlate time between their >>>>>ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
"The transfer function of a target limits the jitter detection
threshold with signals of echolocating FM-bats" >>><https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are
able to discriminate alternations in delay down to 10 ns, which
appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result" >>><https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution
hitherto unknown in any animal, namely a 10-ns jitter detection
threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity: >>><https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
So that's a source of the 10ns stuff. The theory is that there was an >>instrumentation error, which is certainly plausible as no biological
system is that fast, so biological researchers are far out of their
domain for sure.
Why do you say that no biological system can be that fast?
Anything less than a microsecond is astounding, inside the gooey head
of a bat flapping its wings mid-air hunting a moth.
Joe
PS: The 100,000 rpm spinner in biology is "ATP Synthase", the enzyme >>system that converts between ADP and ATP in the mitochondria (in
animals) and chloroplasts (in plants).
.<https://en.wikipedia.org/wiki/ATP_synthase>
JMG
DNA helicase, the little gadget that splits our DNA when a cell
divides, spins at about 10,000 RPM.
<Rotating biological motors were declared to be impossible, and
rotating flagellum were known to be optical illusions.> Once.
Google the <> above.
On 12/06/2026 12:12 am, john larkin wrote:
On Thu, 11 Jun 2026 17:13:17 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 11/06/2026 3:29 pm, john larkin wrote:
On Wed, 10 Jun 2026 19:32:15 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>> wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>>>> wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>>>>> wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>>> wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>>>>>>>>>> legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
<snip>
Sigh. I initially mentioned that there might have been some confusion >>>>> between response time and jitter. Now, you add DNA replication to the >>>>> confusion. Time for a sanity check.
What got my attention was the radical difference between the alleged >>>>> 10 nsec nervous response time in bats, and the much slower nerve
conduction times in humans. (I couldn't find specific numbers for
bats).
"Nerve conduction velocity"
<https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to >>>>> over 120 m/s".
I once watched a "cloud" of fruit bats emerging from the trees at
dusk:
<https://en.wikipedia.org/wiki/Egyptian_fruit_bat>
I don't know how many there were, but my guess(tm) is in the
thousands. The bats were not using their sonar for locating moths.
Instead, they were looking for fruit and using their sonar to prevent >>>>> mid-air collisions. I watched carefully and didn't see any collisions >>>>> or bats falling from the sky. In order to do that, the muscles that >>>>> move the bats wings need to quickly respond to brain signals and the >>>>> muscles need to move quite fast. 10 nsec response time isn't going to >>>>> work when the signals move at 0.5 m/s to over 120 m/s. A nerve
impulse moves at perhaps 1 meter/sec (or 10 nanometers in 10
nanoseconds). A 10 nsec nerve impulse will have moved a microscopic >>>>> distance.
For the record, I said "nanosecond resolution" not 10 nanoseconds.
But it is still nonsense.
And yes, nerve impulses are assumed move about a meter per second, yet >>>> people play table tennis.
One possible explanation is that nerve impulses don't move meters per
second.
Possible, but not plausible. People have been measuring nerve impulse
speed for quite a while now.
They measure what's easy to measure, an electrical impulse. Maybe
that's not the information being sent.
The electrical impulse isn't all that easy to measure, but at least it
is visible, if you measure carefully enough.
You can hypothesise all sorts of magic connections, but until you spell
out what one of them might be and how you'd measure it, you are just
going in for hand-waving mysticism.
It all looks very as if you got caught being even stupider than usual,
and are now trying to back off.
On Wed, 10 Jun 2026 22:29:45 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Wed, 10 Jun 2026 19:32:15 -0700, Jeff Liebermann <jeffl@cruzio.com> >>wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>>wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>>>wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info >>>>>>>>>>> on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick >>>>>>>>>>> this up in time to remove the TI part number from your list >>>>>>>>>>> of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI >>>>>>>>>>> never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>>>>> certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to
be close to particularly good brains.
I read a study that says that bats can correlate time between their >>>>>>>ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find >>>>>>that study?
"The transfer function of a target limits the jitter detection >>>>>threshold with signals of echolocating FM-bats" >>>>><https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are >>>>>able to discriminate alternations in delay down to 10 ns, which >>>>>appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result" >>>>><https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution >>>>>hitherto unknown in any animal, namely a 10-ns jitter detection >>>>>threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity: >>>>><https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
So that's a source of the 10ns stuff. The theory is that there was an >>>>instrumentation error, which is certainly plausible as no biological >>>>system is that fast, so biological researchers are far out of their >>>>domain for sure.
It's only my best guess(tm). I didn't have much success at finding
the oldest bat related citation that included a 10 nsec response time. >>>>Joe
PS: The 100,000 rpm spinner in biology is "ATP Synthase", the enzyme >>>>system that converts between ADP and ATP in the mitochondria (in >>>>animals) and chloroplasts (in plants).
.<https://en.wikipedia.org/wiki/ATP_synthase>
JMG
Sigh. I initially mentioned that there might have been some confusion >>>between response time and jitter. Now, you add DNA replication to the >>>confusion. Time for a sanity check.
What got my attention was the radical difference between the alleged
10 nsec nervous response time in bats, and the much slower nerve >>>conduction times in humans. (I couldn't find specific numbers for
bats).
"Nerve conduction velocity" >>><https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to >>>over 120 m/s".
I once watched a "cloud" of fruit bats emerging from the trees at
dusk:
<https://en.wikipedia.org/wiki/Egyptian_fruit_bat>
I don't know how many there were, but my guess(tm) is in the
thousands. The bats were not using their sonar for locating moths. >>>Instead, they were looking for fruit and using their sonar to prevent >>>mid-air collisions. I watched carefully and didn't see any collisions
or bats falling from the sky. In order to do that, the muscles that
move the bats wings need to quickly respond to brain signals and the >>>muscles need to move quite fast. 10 nsec response time isn't going to >>>work when the signals move at 0.5 m/s to over 120 m/s. A nerve
impulse moves at perhaps 1 meter/sec (or 10 nanometers in 10 >>>nanoseconds). A 10 nsec nerve impulse will have moved a microscopic >>>distance.
For the record, I said "nanosecond resolution" not 10 nanoseconds.
True. Please note that the URL's I provided were not in response to
your posting. I was responding to a question by joegwinn@comcast.net: >Message-ID: <bueg2l5gtditthqkhv407dcr924p5c07qd@4ax.com>
"Bats are pretty good, but that seems a bit too good. Can you find
that study?"
And yes, nerve impulses are assumed move about a meter per second, yet >>people play table tennis.
One possible explanation is that nerve impulses don't move meters per >>second.
Methinks the mechanism might be similar to measuring the speed of
electrons in wires. Energy transmission in a wire moves at near light
speed. Electron drift velocity in wires (the movement of individual >electrons) is about 1 mm/sec, which is much slower. I suspected that
nerve impulse transmission in bats might be similar. However, my
analogy breaks down because nerve impulse velocity can be 1 to 100 >meters/sec, which is still much slower than near light speed (3*10^8 >meters/sec).
"Nerve conduction velocity" ><https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to
over 120 m/s"
"Bats are surprisingly fast decision makers" ><https://www.sdu.dk/en/om-sdu/fakulteterne/naturvidenskab/nyheder-2015/2015_03_18_bat_decision>
"Sometimes we also see reaction times of only 20 milliseconds in bats,
for instance in response to loud sounds, but that is a simple reflex
reaction that does not require brain work".
20 msec response time isn't light speed it's a long way from 10 nsec.
If the flying bat is on auto-pilot, then it's making 50 course
corrections every second. Offhand, methinks that might be sufficient
to avoid mid-air collisions with other bats. Even if 10 nsec
resolution were possible, it would be overkill for a bat.
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info >>>>>>>>> on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick >>>>>>>>> this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI >>>>>>>>> never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>>>be close to particularly good brains.
I read a study that says that bats can correlate time between their >>>>>ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
"The transfer function of a target limits the jitter detection
threshold with signals of echolocating FM-bats" >>><https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are
able to discriminate alternations in delay down to 10 ns, which
appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result" >>><https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution
hitherto unknown in any animal, namely a 10-ns jitter detection
threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity: >>><https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
So that's a source of the 10ns stuff. The theory is that there was an >>instrumentation error, which is certainly plausible as no biological
system is that fast, so biological researchers are far out of their
domain for sure.
It's only my best guess(tm). I didn't have much success at finding
the oldest bat related citation that included a 10 nsec response time.
Joe
PS: The 100,000 rpm spinner in biology is "ATP Synthase", the enzyme >>system that converts between ADP and ATP in the mitochondria (in
animals) and chloroplasts (in plants).
.<https://en.wikipedia.org/wiki/ATP_synthase>
JMG
Sigh. I initially mentioned that there might have been some confusion >between response time and jitter. Now, you add DNA replication to the >confusion. Time for a sanity check.
What got my attention was the radical difference between the alleged
10 nsec nervous response time in bats, and the much slower nerve
conduction times in humans. (I couldn't find specific numbers for
bats).
"Nerve conduction velocity" ><https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to
over 120 m/s".
I once watched a "cloud" of fruit bats emerging from the trees at
dusk:
<https://en.wikipedia.org/wiki/Egyptian_fruit_bat>
I don't know how many there were, but my guess(tm) is in the
thousands. The bats were not using their sonar for locating moths.
Instead, they were looking for fruit and using their sonar to prevent
mid-air collisions. I watched carefully and didn't see any collisions
or bats falling from the sky. In order to do that, the muscles that
move the bats wings need to quickly respond to brain signals and the
muscles need to move quite fast. 10 nsec response time isn't going to
work when the signals move at 0.5 m/s to over 120 m/s. A nerve
impulse moves at perhaps 1 meter/sec (or 10 nanometers in 10
nanoseconds). A 10 nsec nerve impulse will have moved a microscopic >distance.
On Wed, 10 Jun 2026 18:02:22 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>>wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info >>>>>>>>>> on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick >>>>>>>>>> this up in time to remove the TI part number from your list >>>>>>>>>> of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI >>>>>>>>>> never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>>>>be close to particularly good brains.
I read a study that says that bats can correlate time between their >>>>>>ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find >>>>>that study?
"The transfer function of a target limits the jitter detection >>>>threshold with signals of echolocating FM-bats" >>>><https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are
able to discriminate alternations in delay down to 10 ns, which
appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result" >>>><https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution
hitherto unknown in any animal, namely a 10-ns jitter detection >>>>threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity: >>>><https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
So that's a source of the 10ns stuff. The theory is that there was an >>>instrumentation error, which is certainly plausible as no biological >>>system is that fast, so biological researchers are far out of their >>>domain for sure.
Why do you say that no biological system can be that fast?
I did not say that, although it was widely believed in the past.
Anything less than a microsecond is astounding, inside the gooey head
of a bat flapping its wings mid-air hunting a moth.
Yes.
Joe
PS: The 100,000 rpm spinner in biology is "ATP Synthase", the enzyme >>>system that converts between ADP and ATP in the mitochondria (in
animals) and chloroplasts (in plants).
.<https://en.wikipedia.org/wiki/ATP_synthase>
JMG
DNA helicase, the little gadget that splits our DNA when a cell
divides, spins at about 10,000 RPM.
<Rotating biological motors were declared to be impossible, and
rotating flagellum were known to be optical illusions.> Once.
Google the <> above.
Yes. It's true that this was believed back in the day when no
microscope of the day could see these little motors.
There were ways to determine the arrangement of atoms in crystals
(X-ray diffraction), and it was possible to analyze such motors to the
degree that they could be made to form good crystals. The motor
assemblies are 10 to 15 nanometers across. Modern electron
microscopes can see them directly as little blobs, but one cannot
figure out the mechanism without using other kinds of data.
Joe
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
Anything less than a microsecond is astounding, inside the gooey head
of a bat flapping its wings mid-air hunting a moth.
To put it in perspective, a microsecond at the velocity of sound in air
corresponds to 0.25mm (or 0.125mm for echolocation distance
measurement).
If nerve impulses travel 100 m/s and a bat's ears are 2 cm apart, the
neural delay between ears is 200 us. And that's modulated by movement, heartbeats, things like that.
Maybe nature doesn't care about our opinions of how it's allowed to
work.
John Larkin
Highland Tech Glen Canyon Design Center
Lunatic Fringe Electronics
On Thu, 11 Jun 2026 13:41:15 -0400, joegwinn@comcast.net wrote:
On Wed, 10 Jun 2026 18:02:22 -0700, john larkin <jl@glen--canyon.com> >>wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>>wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>>>wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info >>>>>>>>>>> on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick >>>>>>>>>>> this up in time to remove the TI part number from your list >>>>>>>>>>> of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI >>>>>>>>>>> never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>>>>> certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to
be close to particularly good brains.
I read a study that says that bats can correlate time between their >>>>>>>ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find >>>>>>that study?
"The transfer function of a target limits the jitter detection >>>>>threshold with signals of echolocating FM-bats" >>>>><https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are >>>>>able to discriminate alternations in delay down to 10 ns, which >>>>>appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result" >>>>><https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution >>>>>hitherto unknown in any animal, namely a 10-ns jitter detection >>>>>threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity: >>>>><https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec>
So that's a source of the 10ns stuff. The theory is that there was an >>>>instrumentation error, which is certainly plausible as no biological >>>>system is that fast, so biological researchers are far out of their >>>>domain for sure.
Why do you say that no biological system can be that fast?
I did not say that, although it was widely believed in the past.
Anything less than a microsecond is astounding, inside the gooey head
of a bat flapping its wings mid-air hunting a moth.
Yes.
Joe
PS: The 100,000 rpm spinner in biology is "ATP Synthase", the enzyme >>>>system that converts between ADP and ATP in the mitochondria (in >>>>animals) and chloroplasts (in plants).
.<https://en.wikipedia.org/wiki/ATP_synthase>
JMG
DNA helicase, the little gadget that splits our DNA when a cell
divides, spins at about 10,000 RPM.
<Rotating biological motors were declared to be impossible, and
rotating flagellum were known to be optical illusions.> Once.
Google the <> above.
Yes. It's true that this was believed back in the day when no
microscope of the day could see these little motors.
There were ways to determine the arrangement of atoms in crystals
(X-ray diffraction), and it was possible to analyze such motors to the >>degree that they could be made to form good crystals. The motor
assemblies are 10 to 15 nanometers across. Modern electron
microscopes can see them directly as little blobs, but one cannot
figure out the mechanism without using other kinds of data.
Joe
The breakthrough was that somebody glued a flagellum down and saw the >bacteria rotate.
On Wed, 10 Jun 2026 12:29:23 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 10/06/2026 2:44 am, john larkin wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info >>>>>>>>> on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick >>>>>>>>> this up in time to remove the TI part number from your list
of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI >>>>>>>>> never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>>> certainly would have when crappy compressed MP3s took over the world. >>>>>>>>
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to >>>>>> be close to particularly good brains.
I read a study that says that bats can correlate time between their
ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find
that study?
Thanks,
Joe
Good grief, just google
bat echolocation nanosecond
You made the claim, you do the googling.
It's not hard to use an internet search engine. You could take a
class.
On Fri, 12 Jun 2026 02:00:02 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 12/06/2026 12:21 am, john larkin wrote:
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
Anything less than a microsecond is astounding, inside the gooey head >>>>> of a bat flapping its wings mid-air hunting a moth.
To put it in perspective, a microsecond at the velocity of sound in air >>>> corresponds to 0.25mm (or 0.125mm for echolocation distance
measurement).
If nerve impulses travel 100 m/s and a bat's ears are 2 cm apart, the
neural delay between ears is 200 us. And that's modulated by movement,
heartbeats, things like that.
Maybe nature doesn't care about our opinions of how it's allowed to
work.
Obviously it doesn't. That doesn't excuse you from picking up
particularly half-baked ideas about how well it might be performing and
posting them here.
Most ideas are half-baked at first. But hostility to ideas guarantees
that you will have none.
We need more goofy ideas; lots more. Then we need to sift out the few
good ones, not club them all to death on first sight.
On Fri, 12 Jun 2026 01:57:15 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 12/06/2026 12:12 am, john larkin wrote:
On Thu, 11 Jun 2026 17:13:17 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 11/06/2026 3:29 pm, john larkin wrote:
On Wed, 10 Jun 2026 19:32:15 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>>> wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>>>>> wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote: >>>>>>>>
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>>>>>> wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>>>>>>>>>>> legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
<snip>
Sigh. I initially mentioned that there might have been some confusion >>>>>> between response time and jitter. Now, you add DNA replication to the >>>>>> confusion. Time for a sanity check.
What got my attention was the radical difference between the alleged >>>>>> 10 nsec nervous response time in bats, and the much slower nerve
conduction times in humans. (I couldn't find specific numbers for >>>>>> bats).
"Nerve conduction velocity"
<https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to >>>>>> over 120 m/s".
I once watched a "cloud" of fruit bats emerging from the trees at
dusk:
<https://en.wikipedia.org/wiki/Egyptian_fruit_bat>
I don't know how many there were, but my guess(tm) is in the
thousands. The bats were not using their sonar for locating moths. >>>>>> Instead, they were looking for fruit and using their sonar to prevent >>>>>> mid-air collisions. I watched carefully and didn't see any collisions >>>>>> or bats falling from the sky. In order to do that, the muscles that >>>>>> move the bats wings need to quickly respond to brain signals and the >>>>>> muscles need to move quite fast. 10 nsec response time isn't going to >>>>>> work when the signals move at 0.5 m/s to over 120 m/s. A nerve
impulse moves at perhaps 1 meter/sec (or 10 nanometers in 10
nanoseconds). A 10 nsec nerve impulse will have moved a microscopic >>>>>> distance.
For the record, I said "nanosecond resolution" not 10 nanoseconds.
But it is still nonsense.
And yes, nerve impulses are assumed move about a meter per second, yet >>>>> people play table tennis.
One possible explanation is that nerve impulses don't move meters per >>>>> second.
Possible, but not plausible. People have been measuring nerve impulse
speed for quite a while now.
They measure what's easy to measure, an electrical impulse. Maybe
that's not the information being sent.
The electrical impulse isn't all that easy to measure, but at least it
is visible, if you measure carefully enough.
You can hypothesise all sorts of magic connections, but until you spell
out what one of them might be and how you'd measure it, you are just
going in for hand-waving mysticism.
It all looks very as if you got caught being even stupider than usual,
and are now trying to back off.
Not a bit. Maybe a complex chemical message travels very fast, and the electrical pulse is a system refresh that chases it.
That would be harder to detect, especially if one wasn't looking for
it.
Have you read "Finding The Mother Tree"? It would be fun to instrument
those fungi filaments in real time.
On Thu, 11 Jun 2026 09:16:05 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Wed, 10 Jun 2026 22:29:45 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Wed, 10 Jun 2026 19:32:15 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>>> wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>>>> wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>> wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>>>>>>>>> legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
20 msec response time isn't light speed it's a long way from 10 nsec.
If the flying bat is on auto-pilot, then it's making 50 course
corrections every second. Offhand, methinks that might be sufficient
to avoid mid-air collisions with other bats. Even if 10 nsec
resolution were possible, it would be overkill for a bat.
Some things happen locally, in the spinal cord or even closer to the
action, without having to send messages to the head and back. The
spinal cord is really just a part of the brain.
But some things, like hitting a baseball, must use an eye-brain-muscle
path fast.
I surprise myself at how fast I can catch something that I drop. This
morning I trapped an orange between the countertop and my belly, in a fraction of a second. Something decided that the belly would work
better than a hand.
I once caught a hot soldering iron in mid-air. Just once. Now
something tells my muscles to grab oranges but not soldering irons.
I surprise myself at how fast I can catch something that I drop. This
morning I trapped an orange between the countertop and my belly, in a fraction of a second. Something decided that the belly would work
better than a hand.
On 12/06/2026 3:38 am, john larkin wrote:
On Fri, 12 Jun 2026 02:00:02 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 12/06/2026 12:21 am, john larkin wrote:
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
Anything less than a microsecond is astounding, inside the gooey head >>>>>> of a bat flapping its wings mid-air hunting a moth.
To put it in perspective, a microsecond at the velocity of sound in air >>>>> corresponds to 0.25mm (or 0.125mm for echolocation distance
measurement).
If nerve impulses travel 100 m/s and a bat's ears are 2 cm apart, the
neural delay between ears is 200 us. And that's modulated by movement, >>>> heartbeats, things like that.
Maybe nature doesn't care about our opinions of how it's allowed to
work.
Obviously it doesn't. That doesn't excuse you from picking up
particularly half-baked ideas about how well it might be performing and
posting them here.
Most ideas are half-baked at first. But hostility to ideas guarantees
that you will have none.
I've got three patents. You've got your name on one. I'm demonstrably
not hostile to new ideas, if they are any good. This isn't any kind of >brain-storming venue, and your attitude is more "gullible sucker" than >"receptive to novel ideas".
We need more goofy ideas; lots more. Then we need to sift out the few
good ones, not club them all to death on first sight.
You might. Talented people come up actual patentable ideas quite
frequently. My father and two of my friends have all managed about 25
each over their careers. People like that can afford to winnow out the >nonsense early - probably because they are whole lot better at it than
you seem to be.
john larkin <jl@glen--canyon.com> wrote:
I surprise myself at how fast I can catch something that I drop. This
morning I trapped an orange between the countertop and my belly, in a
fraction of a second. Something decided that the belly would work
better than a hand.
Whwn I started work in a radio factory I had to train myself NOT to
catch things thrown at me - they were sometimes fully-charged 500v >capacitors.
When I later worked in a laboratory, the chief technician shouted
"catch" as he threw a 1-litre round-bottomed flask at me; I stood still
and watched it shatter on the floor. He was most upset.
On Fri, 12 Jun 2026 16:34:22 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 12/06/2026 3:38 am, john larkin wrote:
On Fri, 12 Jun 2026 02:00:02 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 12/06/2026 12:21 am, john larkin wrote:
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid >>>>> (Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
Anything less than a microsecond is astounding, inside the gooey head >>>>>>> of a bat flapping its wings mid-air hunting a moth.
To put it in perspective, a microsecond at the velocity of sound in air >>>>>> corresponds to 0.25mm (or 0.125mm for echolocation distance
measurement).
If nerve impulses travel 100 m/s and a bat's ears are 2 cm apart, the >>>>> neural delay between ears is 200 us. And that's modulated by movement, >>>>> heartbeats, things like that.
Maybe nature doesn't care about our opinions of how it's allowed to
work.
Obviously it doesn't. That doesn't excuse you from picking up
particularly half-baked ideas about how well it might be performing and >>>> posting them here.
Most ideas are half-baked at first. But hostility to ideas guarantees
that you will have none.
I've got three patents. You've got your name on one. I'm demonstrably
not hostile to new ideas, if they are any good. This isn't any kind of
brain-storming venue, and your attitude is more "gullible sucker" than
"receptive to novel ideas".
We need more goofy ideas; lots more. Then we need to sift out the few
good ones, not club them all to death on first sight.
You might. Talented people come up actual patentable ideas quite
frequently. My father and two of my friends have all managed about 25
each over their careers. People like that can afford to winnow out the
nonsense early - probably because they are whole lot better at it than
you seem to be.
Patents are mostly silly ego trips or VC hype. About half are
abandoned. Only a couple per cent earn more than they cost.
I'd rather design stuff and sell it. I know of only two cases where
someone copied our designs, and both are out of business now.
On 13/06/2026 12:36 am, john larkin wrote:
On Fri, 12 Jun 2026 16:34:22 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 12/06/2026 3:38 am, john larkin wrote:
On Fri, 12 Jun 2026 02:00:02 +1000, Bill Sloman <bill.sloman@ieee.org> >>>> wrote:
On 12/06/2026 12:21 am, john larkin wrote:
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid >>>>>> (Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
Anything less than a microsecond is astounding, inside the gooey >>>>>>>> head
of a bat flapping its wings mid-air hunting a moth.
To put it in perspective, a microsecond˙ at the velocity of sound >>>>>>> in air
corresponds to 0.25mm (or 0.125mm for echolocation distance
measurement).
If nerve impulses travel 100 m/s and a bat's ears are 2 cm apart, the >>>>>> neural delay between ears is 200 us. And that's modulated by
movement,
heartbeats, things like that.
Maybe nature doesn't care about our opinions of how it's allowed to >>>>>> work.
Obviously it doesn't. That doesn't excuse you from picking up
particularly half-baked ideas about how well it might be performing >>>>> and
posting them here.
Most ideas are half-baked at first. But hostility to ideas guarantees
that you will have none.
I've got three patents. You've got your name on one. I'm demonstrably
not hostile to new ideas, if they are any good. This isn't any kind of
brain-storming venue, and your attitude is more "gullible sucker" than
"receptive to novel ideas".
We need more goofy ideas; lots more. Then we need to sift out the few
good ones, not club them all to death on first sight.
You might. Talented people come up actual patentable ideas quite
frequently. My father and two of my friends have all managed about 25
each over their careers. People like that can afford to winnow out the
nonsense early - probably because they are whole lot better at it than
you seem to be.
Patents are mostly silly ego trips or VC hype. About half are
abandoned. Only a couple per cent earn more than they cost.
Patents are expensive. That winnows out a lot of the silly ego trips and
the VC hype. I abandoned a provisional patent (which is very cheap) when
I realised that it was based on a misconception. On the other hand
Tektronix abandoned a patent on a better confocal microscope that made a friend of mine $A12 million.
They are rather like venture capital investments, where nineteen out of twenty fail, but the one in twenty success pays out more than the
nineteen failures cost.
The point about patents is that they aren't obvious to those skilled in
the art. They are an original solution to a problem - whether the
problem is worth solving is a different question.
I'd rather design stuff and sell it. I know of only two cases where
someone copied our designs, and both are out of business now.
You'd like to design stuff and sell it. You design skills aren't
impressive, but you do seem to be able sell what you can cobble together.
If your design skills were more impressive your stuff might be worth copying.
On Thu, 11 Jun 2026 11:03:52 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Thu, 11 Jun 2026 13:41:15 -0400, joegwinn@comcast.net wrote:
On Wed, 10 Jun 2026 18:02:22 -0700, john larkin <jl@glen--canyon.com> >>>wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>>>wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:So that's a source of the 10ns stuff. The theory is that there was an >>>>>instrumentation error, which is certainly plausible as no biological >>>>>system is that fast, so biological researchers are far out of their >>>>>domain for sure.
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--canyon.com> >>>>>>>wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>>wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>>>>>>>>> legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
https://www.youtube.com/watch?v=22ZmmZ67SMY
NE5532
. . . . just in case somebody is actually searching for info >>>>>>>>>>>> on an actual part number.
If you're wired into the ON/TI/NXP PCN channels, you'll pick >>>>>>>>>>>> this up in time to remove the TI part number from your list >>>>>>>>>>>> of alternates.
Audio mfrs are pretty paranoid about sources. Chances are TI >>>>>>>>>>>> never showed up, in the first place.
If I hadn?t stopped talking audio design seriously in about 1980, I >>>>>>>>>>> certainly would have when crappy compressed MP3s took over the world.
Golden ears, my left buttock.
The ears are close to the brain for a reason. Golden ears don't seem to
be close to particularly good brains.
I read a study that says that bats can correlate time between their >>>>>>>>ears with nanosecond resolution. Pretty good for wet stuff.
Bats are pretty good, but that seems a bit too good. Can you find >>>>>>>that study?
"The transfer function of a target limits the jitter detection >>>>>>threshold with signals of echolocating FM-bats" >>>>>><https://pubmed.ncbi.nlm.nih.gov/16395614/>
"Some investigators have obtained results indicating that bats are >>>>>>able to discriminate alternations in delay down to 10 ns, which >>>>>>appears incredible for purely physical reasons."
"Bat sonar: an alternative interpretation of the 10-ns jitter result" >>>>>><https://pubmed.ncbi.nlm.nih.gov/9528108/>
"In 1990 Simmons et al. reported evidence of a time resolution >>>>>>hitherto unknown in any animal, namely a 10-ns jitter detection >>>>>>threshold in echolocating bats."
Google Scholar produces additional papers on bat echolocation acuity: >>>>>><https://scholar.google.com/scholar?q=bat%20echolocation%2010%20nsec> >>>>>
Why do you say that no biological system can be that fast?
I did not say that, although it was widely believed in the past.
Anything less than a microsecond is astounding, inside the gooey head >>>>of a bat flapping its wings mid-air hunting a moth.
Yes.
Joe
PS: The 100,000 rpm spinner in biology is "ATP Synthase", the enzyme >>>>>system that converts between ADP and ATP in the mitochondria (in >>>>>animals) and chloroplasts (in plants).
.<https://en.wikipedia.org/wiki/ATP_synthase>
JMG
DNA helicase, the little gadget that splits our DNA when a cell >>>>divides, spins at about 10,000 RPM.
<Rotating biological motors were declared to be impossible, and >>>>rotating flagellum were known to be optical illusions.> Once.
Google the <> above.
Yes. It's true that this was believed back in the day when no
microscope of the day could see these little motors.
There were ways to determine the arrangement of atoms in crystals
(X-ray diffraction), and it was possible to analyze such motors to the >>>degree that they could be made to form good crystals. The motor >>>assemblies are 10 to 15 nanometers across. Modern electron
microscopes can see them directly as little blobs, but one cannot
figure out the mechanism without using other kinds of data.
Joe
The breakthrough was that somebody glued a flagellum down and saw the >>bacteria rotate.
Yes, that was irrefutable. Even if they could not see what was going
on.
I do recall the initial announcement of the effect of tethering the
flagellum to a surface - the bacteria rotated at a few Hz. Ended that >debate.
On 13/06/2026 12:36 am, john larkin wrote:
On Fri, 12 Jun 2026 16:34:22 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 12/06/2026 3:38 am, john larkin wrote:
On Fri, 12 Jun 2026 02:00:02 +1000, Bill Sloman <bill.sloman@ieee.org> >>>> wrote:
On 12/06/2026 12:21 am, john larkin wrote:
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid >>>>>> (Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
Anything less than a microsecond is astounding, inside the gooey head >>>>>>>> of a bat flapping its wings mid-air hunting a moth.
To put it in perspective, a microsecond at the velocity of sound in air
corresponds to 0.25mm (or 0.125mm for echolocation distance
measurement).
If nerve impulses travel 100 m/s and a bat's ears are 2 cm apart, the >>>>>> neural delay between ears is 200 us. And that's modulated by movement, >>>>>> heartbeats, things like that.
Maybe nature doesn't care about our opinions of how it's allowed to >>>>>> work.
Obviously it doesn't. That doesn't excuse you from picking up
particularly half-baked ideas about how well it might be performing and >>>>> posting them here.
Most ideas are half-baked at first. But hostility to ideas guarantees
that you will have none.
I've got three patents. You've got your name on one. I'm demonstrably
not hostile to new ideas, if they are any good. This isn't any kind of
brain-storming venue, and your attitude is more "gullible sucker" than
"receptive to novel ideas".
We need more goofy ideas; lots more. Then we need to sift out the few
good ones, not club them all to death on first sight.
You might. Talented people come up actual patentable ideas quite
frequently. My father and two of my friends have all managed about 25
each over their careers. People like that can afford to winnow out the
nonsense early - probably because they are whole lot better at it than
you seem to be.
Patents are mostly silly ego trips or VC hype. About half are
abandoned. Only a couple per cent earn more than they cost.
Patents are expensive. That winnows out a lot of the silly ego trips and
the VC hype. I abandoned a provisional patent (which is very cheap) when
I realised that it was based on a misconception. On the other hand
Tektronix abandoned a patent on a better confocal microscope that made a >friend of mine $A12 million.
They are rather like venture capital investments, where nineteen out of >twenty fail, but the one in twenty success pays out more than the
nineteen failures cost.
The point about patents is that they aren't obvious to those skilled in
the art. They are an original solution to a problem - whether the
problem is worth solving is a different question.
I'd rather design stuff and sell it. I know of only two cases where
someone copied our designs, and both are out of business now.
You'd like to design stuff and sell it. You design skills aren't
impressive, but you do seem to be able sell what you can cobble together.
If your design skills were more impressive your stuff might be worth >copying.
On 12/06/2026 2:16 am, Jeff Liebermann wrote:
On Wed, 10 Jun 2026 22:29:45 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Wed, 10 Jun 2026 19:32:15 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
On Wed, 10 Jun 2026 17:28:51 -0400, joegwinn@comcast.net wrote:
On Tue, 09 Jun 2026 16:15:44 -0700, Jeff Liebermann <jeffl@cruzio.com> >>>>> wrote:
On Tue, 09 Jun 2026 12:16:26 -0400, joegwinn@comcast.net wrote:
On Mon, 08 Jun 2026 10:47:07 -0700, john larkin <jl@glen--
canyon.com>
wrote:
On Mon, 8 Jun 2026 15:44:19 +1000, Bill Sloman
<bill.sloman@ieee.org>
wrote:
On 8/06/2026 4:49 am, Phil Hobbs wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: >>>>>>>>>>> legg <legg@nospam.magma.ca> wrote:
On Wed, 3 Jun 2026 23:10:06 +1000, Chris Jones
<lugnut808@spam.yahoo.com> wrote:
<snip>
And yes, nerve impulses are assumed move about a meter per second, yet
people play table tennis.
One possible explanation is that nerve impulses don't move meters per
second.
Methinks the mechanism might be similar to measuring the speed of
electrons in wires.˙ Energy transmission in a wire moves at near light
speed.˙ Electron drift velocity in wires (the movement of individual
electrons) is about 1 mm/sec, which is much slower.˙ I suspected that
nerve impulse transmission in bats might be similar.˙ However, my
analogy breaks down because nerve impulse velocity can be 1 to 100
meters/sec, which is still much slower than near light speed (3*10^8
meters/sec).
"Nerve conduction velocity"
<https://en.wikipedia.org/wiki/Nerve_conduction_velocity>
"The speed of nerve impulse transmission ranges from about 0.5 m/s to
over 120 m/s"
"Bats are surprisingly fast decision makers"
<https://www.sdu.dk/en/om-sdu/fakulteterne/naturvidenskab/
nyheder-2015/2015_03_18_bat_decision>
"Sometimes we also see reaction times of only 20 milliseconds in bats,
for instance in response to loud sounds, but that is a simple reflex
reaction that does not require brain work".
20 msec response time isn't light speed it's a long way from 10 nsec.
If the flying bat is on auto-pilot, then it's making 50 course
corrections every second.˙ Offhand, methinks that might be sufficient
to avoid mid-air collisions with other bats.˙ Even if 10 nsec
resolution were possible, it would be overkill for a bat.
Caroline Palmer's Ph.D. thesis is on the timing in skilled piano
playing. I've got a copy.
https://www.mcgill.ca/psychology/caroline-palmer
Essentially the piano key has to get the hammer to hit the string within
˙10msec of the desired time to let the performer get the desired
response from the listener. She's got a very well-instrumented piano
that let her document that.
We probably do as well as bats in our own areas of interest.
On Sat, 13 Jun 2026 02:31:22 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 13/06/2026 12:36 am, john larkin wrote:
On Fri, 12 Jun 2026 16:34:22 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 12/06/2026 3:38 am, john larkin wrote:
On Fri, 12 Jun 2026 02:00:02 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:
On 12/06/2026 12:21 am, john larkin wrote:
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid >>>>>>> (Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
If your design skills were more impressive your stuff might be worth
copying.
Sounds like our designs are perfectly calibrated: good enough to sell
but not good enough to copy.
I used to attend some physics conferences and hang out in the bar with competitors. We'd share what we were working on. In a small market, it doesn't make sense to have two vendors do the same stuff.
On 13/06/2026 5:37 am, john larkin wrote:
On Sat, 13 Jun 2026 02:31:22 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 13/06/2026 12:36 am, john larkin wrote:
On Fri, 12 Jun 2026 16:34:22 +1000, Bill Sloman <bill.sloman@ieee.org> >>>> wrote:
On 12/06/2026 3:38 am, john larkin wrote:
On Fri, 12 Jun 2026 02:00:02 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>> wrote:
On 12/06/2026 12:21 am, john larkin wrote:
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid >>>>>>>> (Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
<snip>
If your design skills were more impressive your stuff might be worth
copying.
Sounds like our designs are perfectly calibrated: good enough to sell
but not good enough to copy.
I used to attend some physics conferences and hang out in the bar with
competitors. We'd share what we were working on. In a small market, it
doesn't make sense to have two vendors do the same stuff.
The aim, as a vendor, is to have stuff that blows the competition out of
the water.
On Sat, 13 Jun 2026 16:32:38 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 13/06/2026 5:37 am, john larkin wrote:
On Sat, 13 Jun 2026 02:31:22 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 13/06/2026 12:36 am, john larkin wrote:
On Fri, 12 Jun 2026 16:34:22 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:
On 12/06/2026 3:38 am, john larkin wrote:
On Fri, 12 Jun 2026 02:00:02 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>> wrote:
On 12/06/2026 12:21 am, john larkin wrote:
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid >>>>>>>>> (Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
<snip>
If your design skills were more impressive your stuff might be worth
copying.
Sounds like our designs are perfectly calibrated: good enough to sell
but not good enough to copy.
I used to attend some physics conferences and hang out in the bar with
competitors. We'd share what we were working on. In a small market, it
doesn't make sense to have two vendors do the same stuff.
The aim, as a vendor, is to have stuff that blows the competition out of
the water.
Not me. The aim is to sell.
On 15/06/2026 8:41 am, john larkin wrote:
On Sat, 13 Jun 2026 16:32:38 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 13/06/2026 5:37 am, john larkin wrote:
On Sat, 13 Jun 2026 02:31:22 +1000, Bill Sloman <bill.sloman@ieee.org> >>>> wrote:
On 13/06/2026 12:36 am, john larkin wrote:
On Fri, 12 Jun 2026 16:34:22 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>> wrote:
On 12/06/2026 3:38 am, john larkin wrote:
On Fri, 12 Jun 2026 02:00:02 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>>> wrote:
On 12/06/2026 12:21 am, john larkin wrote:
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid >>>>>>>>>> (Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
<snip>
If your design skills were more impressive your stuff might be worth >>>>> copying.
Sounds like our designs are perfectly calibrated: good enough to sell
but not good enough to copy.
I used to attend some physics conferences and hang out in the bar with >>>> competitors. We'd share what we were working on. In a small market, it >>>> doesn't make sense to have two vendors do the same stuff.
The aim, as a vendor, is to have stuff that blows the competition out of >>> the water.
Not me. The aim is to sell.
Having a significantly better product than your competitors does make it >easier to sell. You may never have been in a position to notice this. In
a really small market, this may not be worth the trouble.
On Mon, 15 Jun 2026 15:38:20 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 15/06/2026 8:41 am, john larkin wrote:
On Sat, 13 Jun 2026 16:32:38 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 13/06/2026 5:37 am, john larkin wrote:
On Sat, 13 Jun 2026 02:31:22 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:
On 13/06/2026 12:36 am, john larkin wrote:
On Fri, 12 Jun 2026 16:34:22 +1000, Bill Sloman <bill.sloman@ieee.org> >>>>>>> wrote:
On 12/06/2026 3:38 am, john larkin wrote:
On Fri, 12 Jun 2026 02:00:02 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 12/06/2026 12:21 am, john larkin wrote:
On Thu, 11 Jun 2026 14:28:44 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
<snip>
If your design skills were more impressive your stuff might be worth >>>>>> copying.
Sounds like our designs are perfectly calibrated: good enough to sell >>>>> but not good enough to copy.
I used to attend some physics conferences and hang out in the bar with >>>>> competitors. We'd share what we were working on. In a small market, it >>>>> doesn't make sense to have two vendors do the same stuff.
The aim, as a vendor, is to have stuff that blows the competition out of >>>> the water.
Not me. The aim is to sell.
Having a significantly better product than your competitors does make it
easier to sell. You may never have been in a position to notice this. In
a really small market, this may not be worth the trouble.
Sure, blowaway products help sell.
But many customers buy stuff because it's reliable, and well
documented, and well supported, and long-term available.
That is especially important in the aerospace and semiconductor industries.
And another powerful reason people will buy from other people is
because they like one another. You may never have been in a position
to notice this.
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