• LED 500mA

    From Edward Rawde@3:633/10 to All on Wednesday, April 08, 2026 16:24:23
    I case anyone is interested, and I know Bill Sloman isn't, this
    seems to meet my LED drive spec.

    The procedure I used to simulate this is as follows.

    Download the pspice model from here and unzip it. https://www.ti.com/product/TPS54302#design-tools-simulation

    Open TPS54302_TRANS.LIB in LTSpice.
    Create Symbol and save the asy file.

    Put the information below in an asc file.
    Open the asc file with Notepad++ and under Encoding if it's not already ANSI convert to ANSI and save it.

    Open the asc file in LTSpice and Mirror (Ctrl-E) and place the symbol.
    Make sure VIN is connected to Vin not EN (which should be open).
    Run the simulation.
    LED current should be stable after 6ms of simulation.

    This has only been tested in LTSpice 26.0.1 and I understand from JM
    that versions earlier than 26 may not work for this simulation.

    Version 4.1
    SHEET 1 3060 936
    WIRE 352 -176 272 -176
    WIRE 448 -176 352 -176
    WIRE 528 -176 448 -176
    WIRE 1296 -176 528 -176
    WIRE 880 -128 592 -128
    WIRE 928 -128 880 -128
    WIRE 1056 -128 1008 -128
    WIRE 1136 -128 1056 -128
    WIRE 1472 -128 1136 -128
    WIRE 1584 -128 1472 -128
    WIRE 1632 -128 1584 -128
    WIRE 880 -48 880 -128
    WIRE 1632 -16 1632 -128
    WIRE 1472 0 1472 -128
    WIRE 1056 64 1056 -128
    WIRE 1136 64 1136 -128
    WIRE 592 112 592 -128
    WIRE 640 112 592 112
    WIRE 880 112 880 16
    WIRE 880 112 832 112
    WIRE 528 144 528 -176
    WIRE 640 144 528 144
    WIRE 640 176 592 176
    WIRE 880 176 832 176
    WIRE 352 192 352 -176
    WIRE 448 192 448 -176
    WIRE 1312 256 1200 256
    WIRE 1424 256 1376 256
    WIRE 272 304 272 -176
    WIRE 1296 368 1296 -176
    WIRE 1376 384 1328 384
    WIRE 1424 384 1424 256
    WIRE 1424 384 1376 384
    WIRE 1520 384 1424 384
    WIRE 1632 384 1632 64
    WIRE 1632 384 1600 384
    WIRE 1680 384 1632 384
    WIRE 1776 384 1744 384
    WIRE 1808 384 1776 384
    WIRE 1856 384 1808 384
    WIRE 2000 384 1920 384
    WIRE 2144 384 2064 384
    WIRE 2288 384 2208 384
    WIRE 2432 384 2352 384
    WIRE 592 400 592 176
    WIRE 672 400 592 400
    WIRE 1200 400 1200 256
    WIRE 1200 400 752 400
    WIRE 1232 400 1200 400
    WIRE 1264 400 1232 400
    WIRE 1376 416 1328 416
    WIRE 1472 416 1472 64
    WIRE 1472 416 1376 416
    WIRE 592 432 592 400
    WIRE 1472 432 1472 416
    WIRE 1776 448 1776 384
    WIRE 272 544 272 384
    WIRE 352 544 352 256
    WIRE 352 544 272 544
    WIRE 448 544 448 256
    WIRE 448 544 352 544
    WIRE 592 544 592 512
    WIRE 592 544 448 544
    WIRE 880 544 880 176
    WIRE 880 544 592 544
    WIRE 1056 544 1056 128
    WIRE 1056 544 880 544
    WIRE 1136 544 1136 128
    WIRE 1136 544 1056 544
    WIRE 1296 544 1296 432
    WIRE 1296 544 1136 544
    WIRE 1472 544 1472 512
    WIRE 1472 544 1296 544
    WIRE 1776 544 1776 512
    WIRE 1776 544 1472 544
    WIRE 2432 544 2432 384
    WIRE 2432 544 1776 544
    WIRE 272 560 272 544
    FLAG 272 560 0
    FLAG 1808 384 led
    FLAG 1376 384 isens
    FLAG 1376 416 iref
    FLAG 1232 400 ifb
    FLAG 1584 -128 vout
    SYMBOL voltage 272 288 R0
    WINDOW 0 -75 16 Left 2
    WINDOW 3 -71 54 Left 2
    WINDOW 123 0 0 Left 0
    WINDOW 39 -185 81 Left 2
    SYMATTR InstName V1
    SYMATTR Value 15
    SYMBOL cap 864 -48 R0
    SYMATTR InstName C1
    SYMATTR Value 100n
    SYMBOL cap 336 192 R0
    SYMATTR InstName C3
    SYMATTR Value 10000n
    SYMBOL cap 432 192 R0
    SYMATTR InstName C2
    SYMATTR Value 100n
    SYMBOL ind 1024 -144 R90
    WINDOW 0 5 56 VBottom 2
    WINDOW 3 32 56 VTop 2
    SYMATTR InstName L1
    SYMATTR Value 0.015m
    SYMATTR SpiceLine Rser=1m
    SYMBOL cap 1040 64 R0
    WINDOW 3 -81 53 Left 2
    SYMATTR Value 22000n
    SYMATTR InstName C4
    SYMBOL cap 1120 64 R0
    SYMATTR InstName C5
    SYMATTR Value 22000n
    SYMBOL res 1648 -32 M0
    WINDOW 0 -37 34 Left 2
    WINDOW 3 -57 63 Left 2
    SYMATTR InstName R5
    SYMATTR Value 0.7
    SYMATTR SpiceLine tol=1 pwr=0.1
    SYMBOL OpAmps\\OP07 1296 336 M0
    WINDOW 0 12 22 Left 2
    WINDOW 3 9 103 Left 2
    SYMATTR InstName U2
    SYMBOL res 1456 528 M180
    WINDOW 0 -40 81 Left 2
    WINDOW 3 -51 46 Left 2
    SYMATTR InstName R7
    SYMATTR Value 470
    SYMATTR SpiceLine tol=1 pwr=0.1
    SYMBOL schottky 1488 0 M0
    WINDOW 0 43 24 Left 2
    WINDOW 3 40 -8 Left 2
    SYMATTR InstName D1
    SYMATTR Value BAT54AHY
    SYMATTR Description Diode
    SYMATTR Type diode
    SYMBOL FerriteBead 1712 384 R90
    WINDOW 0 -16 0 VBottom 2
    SYMATTR InstName L2
    SYMATTR Value 6?
    SYMATTR SpiceLine Ipk=3 Rser=0.0102 Rpar=1220 Cpar=1.9p
    SYMBOL LED 1856 400 R270
    WINDOW 0 72 32 VTop 2
    WINDOW 3 0 32 VBottom 2
    SYMATTR InstName LED1
    SYMATTR Value LXZ1-PB01
    SYMBOL LED 2000 400 R270
    WINDOW 0 72 32 VTop 2
    WINDOW 3 0 32 VBottom 2
    SYMATTR InstName LED2
    SYMATTR Value LXZ1-PB01
    SYMBOL LED 2144 400 R270
    WINDOW 0 72 32 VTop 2
    WINDOW 3 0 32 VBottom 2
    SYMATTR InstName LED3
    SYMATTR Value LXZ1-PB01
    SYMBOL LED 2288 400 R270
    WINDOW 0 72 32 VTop 2
    WINDOW 3 0 32 VBottom 2
    SYMATTR InstName LED4
    SYMATTR Value LXZ1-PB01
    SYMBOL cap 1376 240 R90
    WINDOW 0 0 32 VBottom 2
    WINDOW 3 32 32 VTop 2
    SYMATTR InstName C8
    SYMATTR Value 1n
    SYMBOL res 1616 368 R90
    WINDOW 0 0 56 VBottom 2
    WINDOW 3 32 56 VTop 2
    SYMATTR InstName R6
    SYMATTR Value 22k
    SYMBOL res 576 416 R0
    SYMATTR InstName R1
    SYMATTR Value 10k
    SYMBOL res 768 384 R90
    WINDOW 0 0 56 VBottom 2
    WINDOW 3 32 56 VTop 2
    SYMATTR InstName R2
    SYMATTR Value 47k
    SYMBOL cap 1760 448 R0
    SYMATTR InstName C6
    SYMATTR Value 1n
    TEXT 320 592 Left 2 !.tran 0 10m 0 20n startup
    TEXT 320 632 Left 2 !.options solver alt



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