* SPICE netlist
XU1 N003 N005 N007 N001 0 N012 N013 N001 N002 0 N011 N001 IN N006 N008 N004 LTC1435A ;pnba OSC)SOFT)Ith)SFB)SGND)Vosense)SEN-)SEN+)ExtVcc)PGND)BG)IntVcc)Vin)SW)Boost)TG
MQ1 N006 N011 0 0 Si4412DY
MQ2 IN N004 N006 N006 Si4412DY
L1 N006 N009 27
R1 N009 OUT 25m
C1 N009 OUT .01
C2 N001 0 4.7
C3 N001 N013 100p
D1 N001 N008 1N5818
C4 N006 N008 .1
C5 OUT 0 220 Rser=50m
C6 N005 0 .001
C7 N003 0 56p
V1 IN 0 23
R2 OUT N012 1.44Meg
R3 N012 0 110K
C8 OUT N012 100p
C9 N012 0 100p
R4 N001 N015 3K
R5 0 N015 15.75K
C10 N010 0 100p
C11 N007 N010 .033
R6 N010 0 1K
C12 N001 N014 .1
Rload OUT 0 10
XU2 N013 N007 0 OUT N009 N001 N015 N014 LT1620S8 ;pnba Sense)Iout)GND)IN-)IN+)Vcc)PROG)AVE
.tran 5m startup

* LTspice schematic (.asc)
Version 4
SHEET 1 1792 1072
WIRE 160 -536 -368 -536
WIRE 336 -536 160 -536
WIRE -144 -520 -576 -520
WIRE 336 -520 336 -536
WIRE -368 -504 -368 -536
WIRE 160 -456 160 -536
WIRE -576 -440 -576 -520
WIRE -544 -440 -576 -440
WIRE -160 -440 -192 -440
WIRE 336 -424 336 -440
WIRE -624 -376 -720 -376
WIRE -544 -376 -560 -376
WIRE 112 -376 -192 -376
WIRE -688 -312 -720 -312
WIRE -544 -312 -624 -312
WIRE 160 -312 160 -360
WIRE 160 -312 -192 -312
WIRE -656 -248 -752 -248
WIRE -544 -248 -656 -248
WIRE -112 -248 -192 -248
WIRE 48 -248 -112 -248
WIRE 160 -248 160 -312
WIRE 160 -248 112 -248
WIRE 240 -248 160 -248
WIRE 368 -248 320 -248
WIRE 384 -248 368 -248
WIRE 480 -248 464 -248
WIRE 544 -248 480 -248
WIRE 640 -248 544 -248
WIRE 784 -248 640 -248
WIRE 896 -248 784 -248
WIRE -752 -232 -752 -248
WIRE 784 -232 784 -248
WIRE 896 -232 896 -248
WIRE 160 -200 160 -248
WIRE -144 -184 -144 -520
WIRE -144 -184 -192 -184
WIRE -112 -184 -144 -184
WIRE 640 -168 640 -248
WIRE -752 -152 -752 -168
WIRE -752 -152 -880 -152
WIRE 544 -152 544 -248
WIRE -880 -136 -880 -152
WIRE -752 -136 -752 -152
WIRE 784 -136 784 -168
WIRE 896 -136 896 -152
WIRE -544 -120 -592 -120
WIRE 112 -120 -192 -120
WIRE -544 -56 -592 -56
WIRE 160 -56 160 -104
WIRE 160 -56 -192 -56
WIRE -880 -40 -880 -72
WIRE -752 -40 -752 -56
WIRE 160 -40 160 -56
WIRE -112 -8 -112 -184
WIRE -64 -8 -112 -8
WIRE 16 -8 0 -8
WIRE -592 40 -592 -56
WIRE 544 40 544 -88
WIRE 544 40 -592 40
WIRE 640 40 640 -88
WIRE 640 40 544 40
WIRE -592 56 -592 40
WIRE 640 56 640 40
WIRE -464 120 -464 24
WIRE -400 120 -464 120
WIRE -272 120 -272 24
WIRE -272 120 -336 120
WIRE -112 120 -112 -8
WIRE -112 120 -272 120
WIRE 112 120 -112 120
WIRE 192 120 112 120
WIRE -592 136 -592 120
WIRE 112 136 112 120
WIRE 640 152 640 136
WIRE -112 184 -112 120
WIRE 192 184 192 120
WIRE -464 248 -464 120
WIRE -256 248 -464 248
WIRE 112 248 112 200
WIRE 112 248 32 248
WIRE -656 328 -656 -248
WIRE -256 328 -656 328
WIRE 192 328 192 264
WIRE 192 328 32 328
WIRE 208 328 192 328
WIRE 304 328 288 328
WIRE -256 408 -288 408
WIRE 112 408 32 408
WIRE 368 408 368 -248
WIRE 368 408 112 408
WIRE 112 440 112 408
WIRE -112 488 -112 472
WIRE -288 536 -288 408
WIRE 112 536 112 504
WIRE 112 536 -288 536
WIRE 480 536 480 -248
WIRE 480 536 112 536
FLAG 160 -40 0
FLAG -112 488 0
FLAG -592 -120 0
FLAG 16 -8 0
FLAG 784 -136 0
FLAG -720 -376 0
FLAG -720 -312 0
FLAG 336 -424 0
FLAG 640 152 0
FLAG -592 136 0
FLAG 304 328 0
FLAG -880 -40 0
FLAG -752 -40 0
FLAG 896 -136 0
FLAG 896 -248 OUT
FLAG 336 -536 IN
SYMBOL POWERPRODUCTS\\LTC1435A -368 -216 R0
SYMATTR InstName U1
SYMBOL NMOS 112 -200 R0
SYMATTR InstName Q1
SYMATTR Value Si4412DY
SYMBOL nmos 112 -456 R0
SYMATTR InstName Q2
SYMATTR Value Si4412DY
SYMBOL ind 224 -232 R270
SYMATTR InstName L1
SYMATTR Value 27
SYMBOL RES 368 -232 R270
SYMATTR InstName R1
SYMATTR Value 25m
SYMBOL cap 96 440 R0
SYMATTR InstName C1
SYMATTR Value .01
SYMBOL cap -64 8 R270
SYMATTR InstName C2
SYMATTR Value 4.7
SYMBOL cap -336 104 R90
SYMATTR InstName C3
SYMATTR Value 100p
SYMBOL schottky -128 -184 M180
SYMATTR InstName D1
SYMATTR Value 1N5818
SYMBOL cap 112 -264 R90
SYMATTR InstName C4
SYMATTR Value .1
SYMBOL polcap 768 -232 R0
SYMATTR InstName C5
SYMATTR Value 220
SYMATTR SpiceLine Rser=50m
SYMBOL cap -624 -328 R90
SYMATTR InstName C6
SYMATTR Value .001
SYMBOL cap -560 -392 R90
SYMATTR InstName C7
SYMATTR Value 56p
SYMBOL VOLTAGE 336 -536 R0
SYMATTR InstName V1
SYMATTR Value 23
SYMBOL res 624 -184 R0
SYMATTR InstName R2
SYMATTR Value 1.44Meg
SYMBOL res 624 40 R0
SYMATTR InstName R3
SYMATTR Value 110K
SYMBOL cap 528 -152 R0
SYMATTR InstName C8
SYMATTR Value 100p
SYMBOL cap -608 56 R0
SYMATTR InstName C9
SYMATTR Value 100p
SYMBOL res 176 168 R0
SYMATTR InstName R4
SYMATTR Value 3K
SYMBOL res 304 312 R90
SYMATTR InstName R5
SYMATTR Value 15.75K
SYMBOL cap -896 -136 R0
SYMATTR InstName C10
SYMATTR Value 100p
SYMBOL cap -768 -232 R0
SYMATTR InstName C11
SYMATTR Value .033
SYMBOL res -768 -152 R0
SYMATTR InstName R6
SYMATTR Value 1K
SYMBOL cap 96 136 R0
SYMATTR InstName C12
SYMATTR Value .1
SYMBOL res 880 -248 R0
SYMATTR InstName Rload
SYMATTR Value 10
SYMBOL PowerProducts\\LT1620S8 -112 328 R0
SYMATTR InstName U2