Version 4 SHEET 1 1388 708 WIRE -192 -176 -512 -176 WIRE -32 -176 -112 -176 WIRE 48 -176 -32 -176 WIRE 128 -176 48 -176 WIRE 304 -176 128 -176 WIRE 736 -176 304 -176 WIRE -32 -112 -32 -176 WIRE 128 -112 128 -176 WIRE 368 -96 240 -96 WIRE 432 -96 368 -96 WIRE 624 -96 496 -96 WIRE 960 -96 848 -96 WIRE 1088 -96 1024 -96 WIRE 1248 -96 1088 -96 WIRE 1280 -96 1248 -96 WIRE 368 -48 368 -96 WIRE 624 -48 624 -96 WIRE 736 -48 736 -176 WIRE 848 -48 848 -96 WIRE 1088 -48 1088 -96 WIRE 1248 -48 1248 -96 WIRE -32 -16 -32 -48 WIRE -304 16 -352 16 WIRE 128 64 128 -32 WIRE 192 64 128 64 WIRE 240 64 240 -96 WIRE 240 64 192 64 WIRE 368 64 368 16 WIRE 624 64 624 32 WIRE 624 64 368 64 WIRE 848 64 848 32 WIRE 1088 64 1088 16 WIRE 1088 64 848 64 WIRE 1248 64 1248 32 WIRE 1248 64 1088 64 WIRE -352 80 -352 16 WIRE 624 128 624 64 WIRE 848 128 848 64 WIRE 304 192 304 -176 WIRE 368 192 304 192 WIRE 464 192 432 192 WIRE 736 192 736 32 WIRE 736 192 544 192 WIRE 784 192 736 192 WIRE -512 208 -512 -176 WIRE -352 208 -352 160 WIRE -224 208 -352 208 WIRE -128 208 -224 208 WIRE -64 208 -128 208 WIRE 128 224 128 64 WIRE -224 240 -224 208 WIRE -128 240 -128 208 WIRE 736 240 736 192 WIRE -352 272 -352 208 WIRE -64 288 -64 208 WIRE -32 288 -64 288 WIRE 368 320 288 320 WIRE 432 320 368 320 WIRE 528 320 432 320 WIRE 656 320 608 320 WIRE 688 320 656 320 WIRE -224 352 -224 320 WIRE -128 352 -128 304 WIRE -128 352 -224 352 WIRE -32 352 -128 352 WIRE 432 352 432 320 WIRE -32 416 -224 416 WIRE 432 432 432 416 WIRE -224 448 -224 416 WIRE 352 448 288 448 WIRE -32 480 -128 480 WIRE 352 512 352 448 WIRE 464 512 352 512 WIRE 528 512 464 512 WIRE 592 512 528 512 WIRE 704 512 672 512 WIRE 736 512 736 336 WIRE 736 512 704 512 WIRE 736 544 736 512 WIRE -224 560 -224 528 WIRE -128 560 -128 480 WIRE -128 560 -224 560 WIRE 528 560 528 512 WIRE -224 576 -224 560 WIRE -512 672 -512 288 WIRE -352 672 -352 352 WIRE -352 672 -512 672 WIRE -224 672 -224 640 WIRE -224 672 -352 672 WIRE 128 672 128 544 WIRE 128 672 -224 672 WIRE 528 672 528 624 WIRE 528 672 128 672 WIRE 736 672 736 624 WIRE 736 672 528 672 WIRE 128 688 128 672 FLAG 128 688 0 FLAG 432 432 0 FLAG -32 -16 0 FLAG 624 128 0 FLAG 848 128 0 FLAG 784 192 vd FLAG 1280 -96 V12 IOPIN 1280 -96 Out FLAG -304 16 v12 IOPIN -304 16 In FLAG 656 320 vg FLAG 368 320 vgo FLAG 464 512 vsi FLAG 704 512 vs FLAG 192 64 vcc FLAG 48 -176 v180f FLAG -512 -176 v180 SYMBOL UC3845B 128 384 R0 SYMATTR InstName U1 SYMATTR Value UC3842B SYMBOL res -240 432 R0 SYMATTR InstName R1 SYMATTR Value 10k SYMBOL res -368 64 R0 SYMATTR InstName R2 SYMATTR Value 18k SYMBOL res -368 256 R0 SYMATTR InstName R3 SYMATTR Value 4.7k SYMBOL res 688 496 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R4 SYMATTR Value 1k SYMBOL cap -240 576 R0 SYMATTR InstName C1 SYMATTR Value 4.7n SYMBOL cap -144 240 R0 WINDOW 0 32 0 Left 0 SYMATTR InstName C2 SYMATTR Value 100p SYMBOL res -240 224 R0 SYMATTR InstName R5 SYMATTR Value 150k SYMBOL res 720 528 R0 SYMATTR InstName R6 SYMATTR Value 0.33 SYMBOL cap 512 560 R0 SYMATTR InstName C3 SYMATTR Value 470p SYMBOL res 624 304 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R7 SYMATTR Value 22 SYMBOL schottky 448 416 R180 WINDOW 0 -32 64 Left 0 WINDOW 3 -80 2 Left 0 SYMATTR InstName D1 SYMATTR Value 1N5819 SYMATTR Description Diode SYMATTR Type diode SYMBOL res 112 -128 R0 SYMATTR InstName R8 SYMATTR Value 56k SYMBOL cap -48 -112 R0 WINDOW 3 48 38 Left 0 WINDOW 39 27 65 Left 0 SYMATTR Value 220µ SYMATTR SpiceLine Rser=0.1 SYMATTR InstName C4 SYMBOL ind2 720 -64 R0 WINDOW 0 44 31 Left 0 WINDOW 3 44 76 Left 0 WINDOW 39 23 121 Left 0 SYMATTR InstName L1 SYMATTR Value 1m SYMATTR SpiceLine Rser=0.1 SYMATTR Type ind SYMBOL ind2 608 48 M180 WINDOW 0 46 82 Left 0 WINDOW 3 48 40 Left 0 WINDOW 39 28 -8 Left 0 SYMATTR InstName L2 SYMATTR Value 50µ SYMATTR SpiceLine Rser=0.1 SYMATTR Type ind SYMBOL schottky 496 -112 R90 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName D2 SYMATTR Value 1N5819 SYMATTR Description Diode SYMATTR Type diode SYMBOL cap 352 -48 R0 WINDOW 3 46 35 Left 0 WINDOW 39 33 64 Left 0 SYMATTR Value 100µ SYMATTR SpiceLine Rser=0.1 SYMATTR InstName C5 SYMBOL ind2 864 48 R180 WINDOW 0 -32 80 Left 0 WINDOW 3 -43 38 Left 0 WINDOW 39 -113 6 Left 0 SYMATTR InstName L3 SYMATTR Value 70µ SYMATTR SpiceLine Rser=0.02 SYMATTR Type ind SYMBOL schottky 960 -80 R270 WINDOW 0 32 32 VTop 0 WINDOW 3 0 32 VBottom 0 SYMATTR InstName D4 SYMATTR Value MBR735 SYMATTR Description Diode SYMATTR Type diode SYMBOL cap 1072 -48 R0 WINDOW 3 44 31 Left 0 WINDOW 39 24 56 Left 0 SYMATTR Value 2200µ SYMATTR SpiceLine Rser=0.01 SYMATTR InstName C7 SYMBOL voltage -512 192 R0 WINDOW 123 0 0 Left 0 WINDOW 39 24 132 Left 0 SYMATTR SpiceLine Rser=1 SYMATTR InstName V1 SYMATTR Value 180 SYMBOL res 1232 -64 R0 SYMATTR InstName R9 SYMATTR Value 2 SYMBOL ind -208 -160 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 5 56 VBottom 0 SYMATTR InstName L4 SYMATTR Value 1µ SYMBOL cap 368 208 R270 WINDOW 0 32 32 VTop 0 WINDOW 3 0 32 VBottom 0 SYMATTR InstName C6 SYMATTR Value 2.2n SYMBOL res 448 208 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName R10 SYMATTR Value 1k SYMBOL nmos 688 240 R0 SYMATTR InstName M1 TEXT -528 -296 Left 0 !.tran 0 2m 0 1u startup TEXT -528 -368 Left 0 !.include uc384x.lib TEXT 768 -168 Left 0 !k l1 l2 l3 0.995 TEXT -528 -408 Left 0 !.ic V(vcc)=15.8 TEXT 240 -624 Left 0 ;Measuring power dissipation of a component\n----------------------------------------------------------------------\nPress the Alt-key and move the cursor over the mosfet. \nDo you see the cursor changing to a thermometer?\nNow press additionally the left mouse key. \nResult: The power disspiation versus time will be plotted in the plot window.\n \nSelect a certain time frame(an integer number of cycles) where the regulator is in steady state . \nClick with the left mouse button in the plot window on the label(formula) you just added.\nThis selects this power versus time function. \nPress the Ctrl-key and then click with the left mouse button on that label. \nA small box will come up with the average power dissipation within the \ndisplayed time frame. Forget the value RMS power. It is meaningless with \na power trace(fromula). TEXT -528 -608 Left 0 ;A 12V/6A Step Down Converter TEXT -528 -440 Left 0 ;Use .ic V(vcc)=15.8 to speedup UC3842 startup. TEXT -528 -328 Left 0 ;Use "startup" option in .tran to overcome a convergence error. TEXT 400 96 Left 0 ;optional\nsnubber TEXT -528 -576 Left 0 ;Transformer coupling K is set to 1.0 for fastest simulation.\nThe simulation time rises by a factor of ten if a more real \nK=0.995 or less is used. The optional snubber is just guess\nwork. I don't know whether it's useful or not here. TEXT -536 -264 Left 0 !.options reltol=0.01 TEXT -536 -240 Left 0 !.options trtol=7 TEXT -368 -240 Left 0 ;Use trtol=7 for fastest simulation, defualt is 1 RECTANGLE Normal 912 96 560 -128 RECTANGLE Normal 576 240 352 144