Version 4
SHEET 1 2740 740
WIRE -800 32 -832 32
WIRE -80 32 -720 32
WIRE 128 32 -80 32
WIRE 208 32 128 32
WIRE 352 32 288 32
WIRE 384 32 352 32
WIRE 496 32 448 32
WIRE 592 32 496 32
WIRE 768 32 592 32
WIRE 784 32 768 32
WIRE 128 64 128 32
WIRE -80 80 -80 32
WIRE 352 96 352 32
WIRE -256 112 -592 112
WIRE -416 144 -512 144
WIRE -240 144 -416 144
WIRE 592 144 592 32
WIRE 160 176 80 176
WIRE 304 176 160 176
WIRE 160 192 160 176
WIRE -592 208 -592 112
WIRE -416 208 -416 144
WIRE -384 208 -416 208
WIRE -240 208 -320 208
WIRE 768 224 768 32
WIRE 496 240 496 32
WIRE 592 256 592 224
WIRE 672 256 592 256
WIRE -336 272 -352 272
WIRE -256 272 -256 112
WIRE -240 272 -256 272
WIRE -592 304 -592 288
WIRE -512 304 -592 304
WIRE 128 304 128 144
WIRE 128 304 80 304
WIRE 224 304 128 304
WIRE 352 304 352 192
WIRE 352 304 304 304
WIRE 592 304 592 256
WIRE -592 320 -592 304
WIRE 352 320 352 304
WIRE -352 336 -352 272
WIRE -240 336 -352 336
WIRE -352 352 -352 336
WIRE 672 384 672 256
WIRE -592 416 -592 400
WIRE -448 416 -592 416
WIRE -592 432 -592 416
WIRE -352 432 -352 416
WIRE -80 432 -80 400
WIRE 160 432 160 272
WIRE 352 432 352 400
WIRE 496 432 496 304
WIRE 592 432 592 384
WIRE -416 496 -416 208
WIRE 672 496 672 448
WIRE 672 496 -416 496
WIRE -592 528 -592 512
WIRE -448 528 -448 416
WIRE 768 528 768 304
WIRE 768 528 -448 528
FLAG -352 432 0
FLAG -80 432 0
FLAG 784 32 out
IOPIN 784 32 Out
FLAG -832 32 0
FLAG 352 432 0
FLAG 592 432 0
FLAG 496 432 0
FLAG -592 528 0
FLAG 160 432 0
SYMBOL nmos 304 96 R0
SYMATTR InstName M1
SYMATTR Value IRF740
SYMBOL ind 192 48 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName L1
SYMATTR Value 10µ
SYMATTR SpiceLine Rser=0.1
SYMBOL schottky 384 48 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D1
SYMATTR Value UPSC600
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL res 576 128 R0
SYMATTR InstName R4
SYMATTR Value 12k
SYMBOL res 576 288 R0
SYMATTR InstName R5
SYMATTR Value 810
SYMBOL cap 480 240 R0
SYMATTR InstName C5
SYMATTR Value 1000µ
SYMBOL res 752 208 R0
SYMATTR InstName Rload
SYMATTR Value 40
SYMBOL PowerProducts\\LT1243 -80 240 R0
SYMATTR InstName U1
SYMBOL res 336 304 R0
SYMATTR InstName R1
SYMATTR Value 10m
SYMBOL res -240 256 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 15k
SYMBOL cap -368 352 R0
SYMATTR InstName C1
SYMATTR Value 1n2
SYMBOL voltage -704 32 M270
WINDOW 0 -19 115 VLeft 2
WINDOW 3 -19 25 VLeft 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 20
SYMBOL diode 656 384 R0
SYMATTR InstName D3
SYMATTR Value 1N4148
SYMBOL res -608 192 R0
SYMATTR InstName R8
SYMATTR Value 2k7
SYMBOL res -608 304 R0
SYMATTR InstName R9
SYMATTR Value 2k6
SYMBOL res -608 416 R0
SYMATTR InstName Rsense1
SYMATTR Value 0R33
SYMBOL res 144 176 R0
SYMATTR InstName R7
SYMATTR Value 30k
SYMBOL res 320 288 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R6
SYMATTR Value 910
SYMBOL cap -320 192 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C2
SYMATTR Value 150p
SYMBOL res 112 48 R0
SYMATTR InstName R3
SYMATTR Value 100k
TEXT -232 480 Left 2 !.tran 0 25m 0 10µ startup uic
TEXT -120 288 Left 2 ;UC3843
TEXT -800 568 Left 2 !.model IRF740 NMOS(Level=3 Gamma=0 Delta=0 Eta=0 Theta=0 Kappa=0 Vmax=0 Xj=0 Tox=100n Uo=600 Phi=.6 Rs=8.563m Kp=20.59u W=.78 L=2u Vto=3.657 Rd=.3915 Rds=1.778MEG Cbd=1.419n Pb=.8 Mj=.5 Fc=.5 Cgso=1.392n Cgdo=146.6p Rg=.9088 Is=17.65p N=1 Tt=570n)
TEXT -664 56 Left 2 ;current control