Version 4.1
SHEET 1 1008 728
WIRE 160 -144 -512 -144
WIRE 224 -144 160 -144
WIRE 16 -112 -128 -112
WIRE 160 -112 160 -144
WIRE 160 -112 80 -112
WIRE 160 -96 160 -112
WIRE 160 0 160 -16
WIRE 240 0 160 0
WIRE -128 16 -128 -112
WIRE 16 16 -128 16
WIRE 160 16 160 0
WIRE 160 16 80 16
WIRE 160 32 160 16
WIRE -512 64 -512 -144
WIRE -128 144 -128 16
WIRE 16 144 -128 144
WIRE 160 144 160 112
WIRE 160 144 80 144
WIRE 224 144 160 144
WIRE 160 192 160 144
WIRE -512 256 -512 144
WIRE 160 304 160 272
WIRE 224 304 160 304
WIRE 160 336 160 304
WIRE -128 480 -128 144
WIRE 160 480 160 416
WIRE 160 480 -128 480
WIRE 160 496 160 480
WIRE 224 496 160 496
WIRE 160 544 160 496
WIRE 160 688 160 624
FLAG 160 688 0
FLAG 224 -144 junction
FLAG 224 144 TO220_copper_tab
FLAG 224 496 ambient
FLAG 224 304 heatsink_body
FLAG -512 256 0
FLAG 240 0 center_of_die
SYMBOL res 144 16 R0
SYMATTR InstName R2
SYMATTR Value 0.68
SYMBOL res 144 176 R0
SYMATTR InstName R3
SYMATTR Value 6
SYMBOL voltage 160 528 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 20
SYMBOL res 144 320 R0
SYMATTR InstName R1
SYMATTR Value 20
SYMBOL cap 80 -128 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C1
SYMATTR Value 2.13m
SYMBOL cap 80 0 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C2
SYMATTR Value 10.6m
SYMBOL cap 80 128 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C3
SYMATTR Value 155m
SYMBOL res 144 -112 R0
SYMATTR InstName R4
SYMATTR Value 0.07
SYMBOL current -512 144 R180
WINDOW 0 24 80 Left 2
WINDOW 3 24 0 Left 2
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName I1
SYMATTR Value PULSE(0 5 0 10u 10u 100u 200u)
TEXT 224 192 Left 1 ;thermal resistance\nfrom TO-220 metal tab to heatsink\n(ie thermal resistance of a silpad or similar insulator)\n6 C/W is from the sil-pad 400 datasheet, for a TO-220 size area\nand 25psi applied pressure, and the 0.007 inch thickness material.
TEXT 224 368 Left 1 ;thermal resistance\nfrom heatsink body to ambient\n(from the heatsink datasheet)\n20C/W is a typical value for a \nsmall TO-220 heatsink
TEXT 224 328 Left 1 ;heatsink body temperature is taken under the TO220 copper tab
TEXT -472 136 Left 2 ;Device dissipation\n(0.5W)
TEXT -80 -64 Left 1 ;thermal capacitance\nof junction
TEXT -80 64 Left 1 ;thermal capacitance\nof bulk of die
TEXT -88 192 Left 1 ;thermal capacitance\nof copper tab
TEXT 240 -56 Left 1 ;thermal resistance\nfrom junction to center of die
TEXT 240 64 Left 1 ;thermal resistance\nfrom bulk of die to copper tab
TEXT -904 328 Left 2 !.tran 0 50 0 5u
TEXT -608 -232 Left 4 ;TO-220 device attached with a silpad to a small heatsink.
TEXT 552 -24 Left 2 ;click on run\nclick on "junction" to plot it.\nclick on "TO220_copper_tab" to plot it.\nclick on "heatsink_body" to plot it.\nclick on "ambient" to plot it.
TEXT 552 -64 Left 4 ;Instructions
TEXT -752 680 Left 0 ;You may republish or reuse this circuit implementation and text providing this line and the following lines are included.\nThis circuit implementation designed by Keith Wallbanks. Originally released on analogsimulation.co.uk\nThis circuit is provided as is without warranty of any kind. This text is intended to implement the MIT licence.