* SPICE netlist
XU1 N006 N004 vcc 0 N005 AD820 ;pnba In+)In-)V+)V-)OUT
R1 N004 input 68k
R2 N006 vm 68k
R3 N005 N004 10k
R4 rtrim N006 10k
R5 rtrim N005 47
V1 vm 0 1.65
V2 input vm 0 AC 1
V3 vcc 0 3.3
R8 rtrim ip 61.9
R9 ip vm 10
C1 N005 N004 33n
XU2 N009 P001 vcc 0 N008 AD820 ;pnba In+)In-)V+)V-)OUT
R10 N007 rtrim 10k
R11 N009 ip 10k
R12 N009 vm 100k
R13 N008 N007 100k
R7 rtrim ip 95
XU3 N001 N003 vcc 0 N002 LT1720 ;pnba In+)In-)V+)V-)OUT
V4 N003 vm PULSE(-0.3 0.3 5m 30n 30n 5m 10m)
V5 N001 0 PULSE(0 3.3 0 5u 0 100n 5u)
R6 sense_out N008 3.3k
C4 sense_out 0 100n
V6 P001 N007 1m
;.ac dec 400 10 1e7
.dc V6 -5m 5m

* LTspice schematic (.asc)
Version 4
SHEET 1 2384 912
WIRE -856 -440 -1064 -440
WIRE -616 -424 -616 -440
WIRE -616 -424 -792 -424
WIRE -584 -424 -584 -440
WIRE -472 -424 -584 -424
WIRE -856 -408 -1064 -408
WIRE -120 -376 -168 -376
WIRE -8 -376 -56 -376
WIRE -1064 -312 -1064 -408
WIRE -168 -280 -168 -376
WIRE -168 -280 -200 -280
WIRE -136 -280 -168 -280
WIRE -56 -280 -72 -280
WIRE -8 -280 -8 -376
WIRE -8 -280 -56 -280
WIRE 136 -280 -8 -280
WIRE -472 -168 -472 -424
WIRE -408 -168 -472 -168
WIRE -296 -168 -408 -168
WIRE -200 -168 -200 -280
WIRE -200 -168 -216 -168
WIRE -200 -136 -200 -168
WIRE -120 -136 -200 -136
WIRE 136 -120 136 -280
WIRE 136 -120 -56 -120
WIRE -120 -104 -200 -104
WIRE 136 -104 136 -120
WIRE -200 -72 -200 -104
WIRE -200 -72 -216 -72
WIRE 136 8 136 -24
WIRE 328 8 136 8
WIRE -200 24 -200 -72
WIRE -104 24 -200 24
WIRE 136 24 136 8
WIRE 136 24 -24 24
WIRE -584 56 -616 56
WIRE 776 56 712 56
WIRE 936 56 856 56
WIRE -1128 72 -1192 72
WIRE -616 72 -616 56
WIRE -616 72 -1048 72
WIRE -584 72 -584 56
WIRE -472 72 -472 -168
WIRE -472 72 -584 72
WIRE 328 104 328 8
WIRE 328 104 264 104
WIRE 392 104 328 104
WIRE 392 136 392 104
WIRE 552 136 392 136
WIRE 664 136 632 136
WIRE 264 152 264 104
WIRE 392 152 392 136
WIRE 664 168 664 136
WIRE 712 168 712 56
WIRE 712 168 664 168
WIRE 936 184 936 56
WIRE 936 184 856 184
WIRE 984 184 936 184
WIRE 1112 184 1064 184
WIRE 1192 184 1112 184
WIRE 696 200 664 200
WIRE 792 200 696 200
WIRE 392 248 392 232
WIRE 392 248 376 248
WIRE 552 248 392 248
WIRE 664 248 664 200
WIRE 664 248 632 248
WIRE 696 264 696 200
WIRE 264 280 264 232
WIRE 328 280 264 280
WIRE 392 280 392 248
WIRE 392 280 328 280
WIRE 1112 280 1112 248
WIRE 328 328 328 280
WIRE 328 456 328 408
FLAG -88 -88 0
FLAG -936 456 0
FLAG -1080 456 0
FLAG -1080 376 vcc
FLAG -88 -152 vcc
FLAG -936 376 vm
FLAG 328 456 vm
FLAG -296 -72 vm
FLAG -1192 72 vm
FLAG 824 216 0
FLAG 696 344 vm
FLAG 1192 184 sense_out
FLAG 328 8 rtrim
FLAG 328 280 ip
FLAG 824 152 vcc
FLAG -408 -168 input
FLAG -1064 -232 vm
FLAG -1144 -440 0
FLAG -824 -456 0
FLAG -824 -392 vcc
FLAG 1112 280 0
SYMBOL Opamps\\AD822 -88 -184 R0
SYMATTR InstName U1
SYMBOL res -200 -184 R90
SYMATTR InstName R1
SYMATTR Value 68k
SYMBOL res -200 -88 R90
SYMATTR InstName R2
SYMATTR Value 68k
SYMBOL res -40 -296 R90
SYMATTR InstName R3
SYMATTR Value 10k
SYMBOL res -8 8 R90
SYMATTR InstName R4
SYMATTR Value 10k
SYMBOL res 152 -8 R180
SYMATTR InstName R5
SYMATTR Value 47
SYMBOL voltage -936 360 R0
SYMATTR InstName V1
SYMATTR Value 1.65
SYMBOL voltage -1032 72 R90
SYMATTR InstName V2
SYMATTR Value 0
SYMATTR Value2 AC 1
SYMBOL voltage -1080 360 R0
SYMATTR InstName V3
SYMATTR Value 3.3
SYMBOL res 376 136 R0
SYMATTR InstName R8
SYMATTR Value 61.9
SYMBOL res 312 312 R0
SYMATTR InstName R9
SYMATTR Value 10
SYMBOL cap -56 -392 R90
SYMATTR InstName C1
SYMATTR Value 33n
SYMBOL Opamps\\AD822 824 120 R0
SYMATTR InstName U2
SYMBOL res 648 120 R90
SYMATTR InstName R10
SYMATTR Value 10k
SYMBOL res 648 232 R90
SYMATTR InstName R11
SYMATTR Value 10k
SYMBOL res 680 248 R0
SYMATTR InstName R12
SYMATTR Value 100k
SYMBOL res 872 40 R90
SYMATTR InstName R13
SYMATTR Value 100k
SYMBOL res 248 136 R0
SYMATTR InstName R7
SYMATTR Value 95
SYMBOL Comparators\\LT1720 -824 -360 M180
SYMATTR InstName U3
SYMBOL voltage -1064 -328 R0
SYMATTR Value PULSE(-0.3 0.3 5m 30n 30n 5m 10m)
SYMATTR InstName V4
SYMBOL voltage -1048 -440 R90
SYMATTR InstName V5
SYMATTR Value PULSE(0 3.3 0 5u 0 100n 5u)
SYMBOL res 1080 168 R90
SYMATTR InstName R6
SYMATTR Value 3.3k
SYMBOL cap 1096 184 R0
SYMATTR InstName C4
SYMATTR Value 100n
SYMBOL voltage 808 168 R90
SYMATTR InstName V6
SYMATTR Value 1m