* SPICE netlist
MQ1 N002 N005 N003 N003 Si4864DY
R1 N001 N002 5m
R2 N001 N009 34K
R3 N010 N009 1.74K
R4 N010 0 2.67K
R5 N003 N007 25.1K
R6 0 N007 3.57K
R7 N003 N011 24K
C1 N014 0 .068
C2 N015 0 .068
C3 N016 0 4
V1 N012 0 3.1
V2 N001 0 PWL(0 0 10u 0 100u 12 6 12)
C4 N003 0 2000
R8 0 N003 10
MQ2 N003 N006 N004 N004 Si4864DY
R9 N005 N008 10
R10 0 N004 .05
V4 N013 0 PWL(0 3.1 1 3.1 +100u 0)
XU1 N009 N010 N014 0 N012 N013 N016 N015 N011 N007 N003 N008 N002 N001 N001 LTC4215-2 uvautoretry=1 ovautoretry=1 ocautoretry=1 ;pnba UV)OV)SS)GND)ON)_EN)Timer)Vcc)GPIO)FB)Source)Gate)Sense-)Sense+)Vdd
V3 N006 0 PWL(0 0 4 0 +100u 12 +200m 12 +100n 0)
.tran 12

* LTspice schematic (.asc)
Version 4
SHEET 1 1968 528
WIRE -568 -264 -984 -264
WIRE -280 -264 -568 -264
WIRE -168 -264 -280 -264
WIRE -152 -264 -168 -264
WIRE -56 -264 -72 -264
WIRE -24 -264 -56 -264
WIRE 168 -264 72 -264
WIRE 392 -264 168 -264
WIRE 504 -264 392 -264
WIRE 600 -264 504 -264
WIRE 712 -264 600 -264
WIRE 792 -264 712 -264
WIRE 984 -264 888 -264
WIRE -984 -248 -984 -264
WIRE 392 -248 392 -264
WIRE 600 -248 600 -264
WIRE 712 -248 712 -264
WIRE 984 -248 984 -264
WIRE 56 -200 56 -216
WIRE -568 -184 -568 -264
WIRE 872 -168 872 -216
WIRE -984 -152 -984 -168
WIRE 392 -152 392 -168
WIRE 392 -152 312 -152
WIRE 504 -152 504 -264
WIRE 600 -152 600 -184
WIRE 712 -152 712 -168
WIRE 984 -152 984 -168
WIRE 392 -120 392 -152
WIRE -280 -104 -280 -264
WIRE -168 -104 -168 -264
WIRE -56 -104 -56 -264
WIRE 56 -104 56 -120
WIRE 168 -104 168 -264
WIRE -568 -88 -568 -104
WIRE -456 -88 -568 -88
WIRE -568 -72 -568 -88
WIRE 872 -72 872 -88
WIRE -456 -40 -456 -88
WIRE -376 -40 -456 -40
WIRE 312 -40 312 -152
WIRE 312 -40 280 -40
WIRE 392 -24 392 -40
WIRE -568 24 -568 8
WIRE -376 24 -568 24
WIRE 504 24 504 -72
WIRE 504 24 280 24
WIRE -568 40 -568 24
WIRE -376 88 -440 88
WIRE 360 88 280 88
WIRE -440 104 -440 88
WIRE 360 104 360 88
WIRE -568 136 -568 120
WIRE -296 184 -296 168
WIRE 24 184 24 168
WIRE 184 184 184 168
WIRE -440 200 -440 184
WIRE -136 200 -136 168
WIRE 360 200 360 184
WIRE -296 264 -296 248
WIRE 24 264 24 248
WIRE 184 264 184 248
FLAG -568 136 0
FLAG -136 200 0
FLAG 392 -24 0
FLAG -296 264 0
FLAG 24 264 0
FLAG 184 264 0
FLAG -440 200 0
FLAG -984 -152 0
FLAG 600 -152 0
FLAG 712 -152 0
FLAG 984 -152 0
FLAG 872 -72 0
FLAG 360 200 0
SYMBOL nmos -24 -216 R270
SYMATTR InstName Q1
SYMATTR Value Si4864DY
SYMBOL res -168 -248 R270
SYMATTR InstName R1
SYMATTR Value 5m
SYMBOL res -584 -200 R0
SYMATTR InstName R2
SYMATTR Value 34K
SYMBOL res -584 24 M180
SYMATTR InstName R3
SYMATTR Value 1.74K
SYMBOL res -584 24 R0
SYMATTR InstName R4
SYMATTR Value 2.67K
SYMBOL res 376 -264 R0
SYMATTR InstName R5
SYMATTR Value 25.1K
SYMBOL res 376 -24 M180
SYMATTR InstName R6
SYMATTR Value 3.57K
SYMBOL res 488 -168 R0
SYMATTR InstName R7
SYMATTR Value 24K
SYMBOL cap -312 184 R0
SYMATTR InstName C1
SYMATTR Value .068
SYMBOL cap 8 184 R0
SYMATTR InstName C2
SYMATTR Value .068
SYMBOL cap 168 184 R0
SYMATTR InstName C3
SYMATTR Value 4
SYMBOL voltage -440 88 R0
SYMATTR InstName V1
SYMATTR Value 3.1
SYMBOL voltage -984 -264 R0
SYMATTR InstName V2
SYMATTR Value PWL(0 0 10u 0 100u 12 6 12)
SYMBOL cap 584 -248 R0
SYMATTR InstName C4
SYMATTR Value 2000
SYMBOL res 696 -152 M180
SYMATTR InstName R8
SYMATTR Value 10
SYMBOL nmos 792 -216 R270
SYMATTR InstName Q2
SYMATTR Value Si4864DY
SYMBOL res 40 -216 R0
SYMATTR InstName R9
SYMATTR Value 10
SYMBOL res 968 -152 M180
SYMATTR InstName R10
SYMATTR Value .05
SYMBOL voltage 360 88 R0
SYMATTR InstName V4
SYMATTR Value PWL(0 3.1 1 3.1 +100u 0)
SYMBOL LTC4215-2 -56 24 R0
SYMATTR InstName U1
SYMBOL voltage 872 -184 R0
SYMATTR InstName V3
SYMATTR Value PWL(0 0 4 0 +100u 12 +200m 12 +100n 0)