Version 4 SHEET 1 4036 1592 WIRE 80 -1008 48 -1008 WIRE 272 -1008 160 -1008 WIRE 368 -1008 272 -1008 WIRE 512 -1008 368 -1008 WIRE 704 -1008 512 -1008 WIRE 1008 -1008 704 -1008 WIRE 368 -992 368 -1008 WIRE 512 -992 512 -1008 WIRE 1008 -992 1008 -1008 WIRE 272 -976 272 -1008 WIRE 704 -944 704 -1008 WIRE 272 -848 272 -912 WIRE 368 -848 368 -912 WIRE 704 -816 704 -864 WIRE -336 -528 -416 -528 WIRE -208 -528 -336 -528 WIRE -48 -528 -208 -528 WIRE 320 -528 -48 -528 WIRE -336 -512 -336 -528 WIRE -208 -512 -208 -528 WIRE 1600 -512 1152 -512 WIRE 1696 -512 1600 -512 WIRE 1712 -512 1696 -512 WIRE 512 -480 480 -480 WIRE 768 -480 512 -480 WIRE 960 -480 768 -480 WIRE 1408 -480 960 -480 WIRE -48 -464 -48 -528 WIRE 1056 -448 1008 -448 WIRE 1088 -448 1056 -448 WIRE 1008 -432 1008 -448 WIRE 1088 -432 1088 -448 WIRE -336 -416 -336 -448 WIRE -208 -416 -208 -448 WIRE 480 -400 480 -416 WIRE 1088 -352 1088 -368 WIRE 768 -320 768 -480 WIRE 960 -320 960 -480 WIRE 1056 -320 1056 -448 WIRE 1152 -320 1152 -512 WIRE 512 -272 512 -480 WIRE 1408 -272 1408 -480 WIRE 320 -240 320 -528 WIRE 1600 -240 1600 -512 WIRE -48 -208 -48 -384 WIRE 16 -208 -48 -208 WIRE 192 -208 16 -208 WIRE -48 -176 -48 -208 WIRE 16 -160 16 -208 WIRE 640 -160 368 -160 WIRE 1552 -160 1280 -160 WIRE -48 -80 -48 -96 WIRE 16 -80 16 -96 WIRE 16 -80 -48 -80 WIRE 512 -64 512 -208 WIRE 640 -64 512 -64 WIRE 1408 -64 1408 -208 WIRE 1408 -64 1280 -64 WIRE 512 -48 512 -64 WIRE 1408 -48 1408 -64 WIRE -48 -32 -48 -80 WIRE -208 32 -336 32 WIRE -160 32 -208 32 WIRE -128 32 -160 32 WIRE -16 32 -48 32 WIRE 16 32 -16 32 WIRE 320 32 320 -144 WIRE 320 32 96 32 WIRE 512 32 512 16 WIRE 512 32 320 32 WIRE 640 32 512 32 WIRE 1408 32 1408 16 WIRE 1408 32 1280 32 WIRE 1600 32 1600 -144 WIRE 1600 32 1408 32 WIRE 1680 32 1600 32 WIRE 1792 32 1760 32 WIRE 1840 32 1792 32 WIRE 1984 32 1920 32 WIRE 2064 32 1984 32 WIRE 320 48 320 32 WIRE 1600 48 1600 32 WIRE 640 128 368 128 WIRE 1552 128 1280 128 WIRE -336 144 -336 32 WIRE -208 144 -208 32 WIRE 320 160 320 144 WIRE 1600 160 1600 144 WIRE -160 224 -160 32 WIRE 448 224 -160 224 WIRE 640 224 448 224 WIRE 1472 224 1280 224 WIRE 1984 224 1984 32 WIRE 1984 224 1472 224 WIRE -336 240 -336 224 WIRE 448 240 448 224 WIRE 1472 240 1472 224 WIRE -208 256 -208 208 WIRE -16 320 -16 32 WIRE 448 320 448 304 WIRE 448 320 -16 320 WIRE 640 320 448 320 WIRE 1472 320 1472 304 WIRE 1472 320 1280 320 WIRE 1792 320 1792 32 WIRE 1792 320 1472 320 WIRE 192 416 192 -208 WIRE 544 416 192 416 WIRE 640 416 544 416 WIRE 1296 416 1280 416 WIRE 1408 416 1360 416 WIRE 640 512 576 512 WIRE 1312 512 1280 512 WIRE 576 528 576 512 WIRE 576 608 576 592 WIRE 784 608 784 576 WIRE 1024 608 1024 576 WIRE 1312 608 1312 512 WIRE 1312 608 1024 608 WIRE 1024 624 1024 608 WIRE 784 704 784 688 FLAG 1600 160 0 FLAG 2064 32 IN FLAG -416 -528 OUT FLAG 320 160 0 FLAG -208 256 0 FLAG -336 240 0 FLAG -336 32 IN FLAG -48 -32 0 FLAG -336 -416 0 FLAG -208 -416 0 FLAG 480 -400 0 FLAG 1408 416 0 FLAG 576 608 0 FLAG 1024 624 0 FLAG 1696 -512 OUT FLAG 368 -848 0 FLAG 784 704 0 FLAG 1008 -352 0 FLAG 1088 -352 0 FLAG 48 -1008 OUT FLAG 272 -848 0 FLAG 544 416 FB FLAG 1008 -1008 OUT_Load FLAG 704 -816 0 SYMBOL LTC3787 960 128 R0 SYMATTR InstName U1 SYMBOL cap 496 -416 R180 WINDOW 3 24 8 Left 2 WINDOW 0 24 56 Left 2 SYMATTR Value 4.7µ SYMATTR InstName C1 SYMBOL cap 1392 -48 R0 SYMATTR InstName C5 SYMATTR Value .1µ SYMBOL schottky 1392 -272 R0 WINDOW 3 23 69 Left 2 SYMATTR Value MBR0540 SYMATTR InstName D2 SYMATTR Description Diode SYMATTR Type diode SYMBOL ind 1776 48 M270 WINDOW 0 37 54 VTop 2 WINDOW 3 5 56 VBottom 2 SYMATTR InstName Lo2 SYMATTR Value {Lo1} SYMATTR SpiceLine Rser={DCR1} SYMBOL cap 1456 240 R0 SYMATTR InstName RsenseFilterC2 SYMATTR Value {RsenseFilterC1} SYMBOL res 1936 16 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName Rsense2 SYMATTR Value {Rsense1} SYMBOL nmos 368 48 M0 WINDOW 0 57 33 Left 2 WINDOW 3 62 73 Left 2 SYMATTR InstName Q2 SYMATTR Value BSC028N06LS3 SYMBOL cap 528 -48 M0 SYMATTR InstName C2 SYMATTR Value .1µ SYMBOL schottky 528 -272 M0 WINDOW 3 23 69 Left 2 SYMATTR Value MBR0540 SYMATTR InstName D1 SYMATTR Description Diode SYMATTR Type diode SYMBOL voltage -336 128 M0 WINDOW 123 0 0 Left 2 WINDOW 39 24 124 Left 2 SYMATTR SpiceLine Rser=200m SYMATTR InstName Vin1 SYMATTR Value {Vin1} SYMBOL cap -192 144 M0 WINDOW 123 25 91 Left 2 SYMATTR Value2 x{nCinb1} SYMATTR InstName Cinb1 SYMATTR Value {Cinb1} SYMBOL ind 0 48 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 5 56 VBottom 2 SYMATTR InstName Lo1 SYMATTR Value {Lo1} SYMATTR SpiceLine Rser={DCR1} SYMBOL res -32 -192 M0 SYMATTR InstName RfbBot1 SYMATTR Value {RfbBot1} SYMBOL res -32 -480 M0 SYMATTR InstName RfbTop1 SYMATTR Value {RfbTop1} SYMBOL cap 32 -160 M0 WINDOW 0 -76 5 Left 2 WINDOW 3 -84 44 Left 2 SYMATTR InstName CfbBot1 SYMATTR Value {CfbBot1} SYMBOL cap -192 -512 M0 WINDOW 123 33 91 Left 2 SYMATTR Value2 x{nCob1} SYMATTR InstName Cob1 SYMATTR Value {Cob1} SYMATTR SpiceLine Rser={ESRb1} Lser={ESLb1} SYMBOL cap -320 -512 M0 WINDOW 123 36 88 Left 2 SYMATTR Value2 x{nCoc1} SYMATTR InstName Coc1 SYMATTR Value {Coc1} SYMATTR SpiceLine Rser={ESRc1} Lser={ESLc1} SYMBOL cap 464 240 M0 SYMATTR InstName RsenseFilterC1 SYMATTR Value {RsenseFilterC1} SYMBOL res -32 48 M270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName Rsense1 SYMATTR Value {Rsense1} SYMBOL cap 1296 400 M90 WINDOW 0 -35 33 VBottom 2 WINDOW 3 -29 35 VTop 2 WINDOW 39 42 146 VTop 2 SYMATTR InstName C3 SYMATTR Value {Cth1} SYMATTR SpiceLine Rser={Rth1} Cpar={Cthp1} SYMBOL cap 560 528 R0 SYMATTR InstName C4 SYMATTR Value 10n SYMBOL res 352 -1008 R0 SYMATTR InstName R1 SYMATTR Value 100 SYMBOL nmos 368 -240 M0 WINDOW 0 57 33 Left 2 WINDOW 3 62 73 Left 2 SYMATTR InstName Q1 SYMATTR Value BSC028N06LS3 SYMBOL nmos 1552 -240 R0 WINDOW 0 57 33 Left 2 WINDOW 3 62 73 Left 2 SYMATTR InstName Q3 SYMATTR Value BSC028N06LS3 SYMBOL nmos 1552 48 R0 WINDOW 0 57 33 Left 2 WINDOW 3 62 73 Left 2 SYMATTR InstName Q4 SYMATTR Value BSC028N06LS3 SYMBOL res 768 592 R0 SYMATTR InstName R2 SYMATTR Value {RFreq_1} SYMBOL voltage 1008 -448 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V2 SYMATTR Value 12 SYMBOL cap 1072 -432 R0 SYMATTR InstName C6 SYMATTR Value 1µ SYMATTR SpiceLine Rser=4m SYMBOL ind 64 -992 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 5 56 VBottom 2 SYMATTR InstName L1 SYMATTR Value 400n SYMATTR SpiceLine Ipk=111 Rser=0.0005 Rpar=37.68 Cpar=0 mfg="Coilcraft" pn="XAL1580-401" SYMBOL polcap 288 -976 M0 WINDOW 123 33 91 Left 2 WINDOW 3 24 56 Left 2 SYMATTR Value 100µ SYMATTR InstName Cob2 SYMATTR SpiceLine V=50 Irms=2.01 Rser=0.043 Lser=0 SYMATTR Description Capacitor SYMATTR Type cap SYMBOL load2 704 -944 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName I1 SYMATTR Value PULSE(0 20 1.5m 100n 100n 100u) TEXT -456 672 Left 2 ;parameter imported from LTPowerCAD Design Tool: TEXT -456 632 Left 2 !.tran 2m startup TEXT -456 600 Left 2 ;If simulation model is not found, please "Sync release". TEXT -456 536 Left 2 ;Note: Simulation is running at the default switching frequency for the part.\nPlease manually adjust for additional switching frequency options. TEXT -456 720 Left 2 !.params Vin1=27 Cinb1=270u CinbESR1=20m nCinb1=4 Cinc1=5.8u CincESR1=2m nCinc1=4 fsw1=254k \n.params RfbTop1=475k RfbBot1=15.8k CfbTop1=0p CfbBot1=0p \n.params Rth1=8.66k Cth1=15000p Cthp1=220p \n.params SenseRs1=4.02k SenseC1=0.047u SenseRp1=7.15k \n.params Rsense1=2m RsenseFilterR1=0 RsenseFilterC1=1n \n.params Lo1=3u DCR1=2.62m \n.params Cob1=100u ESRb1=28m ESLb1=3.8n nCob1=4 \n.params Coc1=4.2u ESRc1=1.9m ESLc1=0.3062n nCoc1=4 \n.params Rfreq_1=43.2k Rfreq2_1=0k \n.params RLoad1=4.24\n.params nQC1=1 nQS1=1 TEXT 1736 -360 Left 2 !;.ic V(OUT) 37\n;.ic V(FB) 1.15\n;.options gminsteps=0\n;.options srcsteps=0\n;.options ptrantau=0 TEXT -80 -888 Left 2 !.save V(out_load)\n.save V(out)\n.save V(in)\n.save V(fb)\n.save I(Lo1)\n.save I(Lo2)\n.save I(I1) TEXT -432 -672 Left 2 !;.ic V(out) = 37\n;.ic V(out_load) = 37\n;.ic V(in) = 27\n;.ic V(fb) = 1.185 TEXT -72 -640 Left 2 !;.options maxord=1