* SPICE netlist
V1 IN 0 PWL(0 0 +10u 12 +100m 12 +10u 92 +250m 12)
R1 IN N008 383K
R2 N010 0 10K
R3 N002 OUT 50m
R4 N003 N004 10
R5 OUT N011 102K
R6 N011 0 4.99K
R7 OUT N007 100K
R8 OUT N009 100K
MQ1 IN N003 N001 N001 FDB33N25
C1 0 N004 6.8n
R9 IN N005 2.2K
R10 N008 N010 90.9K
C2 N012 0 6.8
D1 0 N005 1N5373B
C3 N005 0 0.1
MQ2 N002 N006 N001 N001 FDB3682
XU1 OUT N002 N006 N001 N004 N005 N005 N008 N010 0 N009 N007 N012 N011 LTC4364-1 ;pnba OUT)SENSE)DGATE)SOURCE)HGATE)VCC)_SHDN)UV)OV)GND)_FLT)ENOUT)TMR)FB
Cload OUT 0 22 Rser=100m
Rload OUT 0 47
.tran 1

* LTspice schematic (.asc)
Version 4
SHEET 1 2480 640
WIRE -600 -320 -1240 -320
WIRE -104 -320 -600 -320
WIRE -24 -320 -104 -320
WIRE 216 -320 72 -320
WIRE 360 -320 216 -320
WIRE 552 -320 456 -320
WIRE 568 -320 552 -320
WIRE 680 -320 648 -320
WIRE 824 -320 680 -320
WIRE 920 -320 824 -320
WIRE 1016 -320 920 -320
WIRE 1080 -320 1016 -320
WIRE 1240 -320 1080 -320
WIRE -1240 -304 -1240 -320
WIRE 536 -304 552 -320
WIRE 696 -304 680 -320
WIRE 1080 -304 1080 -320
WIRE 1240 -304 1240 -320
WIRE 824 -272 824 -320
WIRE -104 -240 -104 -320
WIRE 56 -240 56 -272
WIRE -1240 -208 -1240 -224
WIRE 1080 -192 1080 -240
WIRE 1240 -192 1240 -224
WIRE 56 -144 56 -160
WIRE 104 -144 56 -144
WIRE 184 -144 168 -144
WIRE 920 -144 920 -320
WIRE -312 -128 -456 -128
WIRE -216 -128 -312 -128
WIRE -104 -128 -104 -160
WIRE -104 -128 -216 -128
WIRE -456 -112 -456 -128
WIRE -312 -112 -312 -128
WIRE -104 -96 -104 -128
WIRE 56 -96 56 -144
WIRE 216 -96 216 -320
WIRE 376 -96 376 -272
WIRE 536 -96 536 -304
WIRE 696 -96 696 -304
WIRE -600 -80 -600 -320
WIRE -456 -32 -456 -48
WIRE -312 -32 -312 -48
WIRE -216 -16 -216 -128
WIRE -200 -16 -216 -16
WIRE 824 -16 824 -192
WIRE 824 -16 792 -16
WIRE -600 32 -600 0
WIRE -488 32 -600 32
WIRE -600 48 -600 32
WIRE 1016 48 1016 -320
WIRE -488 64 -488 32
WIRE -200 64 -488 64
WIRE 920 64 920 -64
WIRE 920 64 792 64
WIRE -600 144 -600 128
WIRE -200 144 -600 144
WIRE 1016 144 1016 128
WIRE 1016 144 792 144
WIRE 1016 160 1016 144
WIRE -600 176 -600 144
WIRE 456 240 456 224
WIRE 120 256 120 224
WIRE 1016 256 1016 240
WIRE -600 272 -600 256
WIRE 456 320 456 304
FLAG -1240 -208 0
FLAG -1240 -320 IN
FLAG -600 272 0
FLAG 120 256 0
FLAG 1016 256 0
FLAG 184 -144 0
FLAG 456 320 0
FLAG -456 -32 0
FLAG -312 -32 0
FLAG 1240 -320 OUT
FLAG 1080 -192 0
FLAG 1240 -192 0
SYMBOL voltage -1240 -320 R0
SYMATTR Value PWL(0 0 +10u 12 +100m 12 +10u 92 +250m 12)
SYMATTR InstName V1
SYMBOL res -616 -96 R0
SYMATTR InstName R1
SYMATTR Value 383K
SYMBOL res -616 160 R0
SYMATTR InstName R2
SYMATTR Value 10K
SYMBOL res 552 -304 R270
SYMATTR InstName R3
SYMATTR Value 50m
SYMBOL res 40 -256 R0
SYMATTR InstName R4
SYMATTR Value 10
SYMBOL res 1000 32 R0
SYMATTR InstName R5
SYMATTR Value 102K
SYMBOL res 1000 144 R0
SYMATTR InstName R6
SYMATTR Value 4.99K
SYMBOL res 808 -288 R0
SYMATTR InstName R7
SYMATTR Value 100K
SYMBOL res 904 -160 R0
SYMATTR InstName R8
SYMATTR Value 100K
SYMBOL nmos -24 -272 R270
SYMATTR InstName Q1
SYMATTR Value FDB33N25
SYMBOL cap 168 -160 R90
SYMATTR Value 6.8n
SYMATTR InstName C1
SYMBOL res -120 -256 R0
SYMATTR InstName R9
SYMATTR Value 2.2K
SYMBOL res -616 32 R0
SYMATTR InstName R10
SYMATTR Value 90.9K
SYMBOL cap 440 240 R0
SYMATTR InstName C2
SYMATTR Value 6.8
SYMBOL zener -472 -48 M180
SYMATTR InstName D1
SYMATTR Value 1N5373B
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL cap -328 -112 R0
SYMATTR Value 0.1
SYMATTR InstName C3
SYMBOL nmos 456 -272 M270
SYMATTR InstName Q2
SYMATTR Value FDB3682
SYMBOL LTC4364-1 296 64 R0
SYMATTR InstName U1
SYMBOL cap 1064 -304 R0
SYMATTR SpiceLine Rser=100m
SYMATTR InstName Cload
SYMATTR Value 22
SYMBOL res 1224 -320 R0
SYMATTR InstName Rload
SYMATTR Value 47