* SPICE netlist
XU1 0 N004 N007 N003 N008 0 N005 N002 AD8421 ;pnba IN-)RG1)RG2)IN+)VEE)REF)OUT)VCC
R1 N004 N007 2490
XU2 N012 N015 N013 opamp Aol=100K GBW=10Meg ;pnba invin)noninvin)out
Vref N014 0 5
R2 N015 N014 620
R3 N013 N012 620
R4 N012 N011 14k
RTrimVref N011 0 2256.4
XU3 N001 N006 Vdet opamp Aol=100K GBW=10Meg ;pnba invin)noninvin)out
R6 N006 N005 1500
Rf Vdet N001 47000
Rg N001 0 2490
R7 N006 N013 60400
C1 N006 0 100n
V2 N008 0 -14
V3 N002 0 14
Vamc1200 N003 0 0 AC 1
XU4 N009 N010 N009 opamp Aol=100K GBW=10Meg ;pnba invin)noninvin)out
R5 N010 N005 1500
C2 N010 0 100n
R8 Vmonitor N009 50
XU5 0 N019 N022 N018 N023 0 N020 N017 AD8421 ;pnba IN-)RG1)RG2)IN+)VEE)REF)OUT)VCC
R9 N019 N022 2490
XU6 N016 N021 Vdet2 opamp Aol=100K GBW=10Meg ;pnba invin)noninvin)out
R10 N021 N020 1500
Rf1 Vdet2 N016 47000
Rg1 N016 0 2490
V1 N023 0 -14
V4 N017 0 14
Vamc1 N018 0 PULSE(-0.025 0.025 1m 1n 1n 10m)
XU7 N024 N025 N024 opamp Aol=100K GBW=10Meg ;pnba invin)noninvin)out
R11 N025 N020 1500
C3 N025 0 100n
R12 Vmonitor2 N024 50
R13 N021 N013 60400
C4 N021 0 100n
XU8 0 N029 N032 N028 N033 0 N030 N027 AD8421 ;pnba IN-)RG1)RG2)IN+)VEE)REF)OUT)VCC
R14 N029 N032 2490
XU9 N026 N031 Vdet3 opamp Aol=100K GBW=10Meg ;pnba invin)noninvin)out
R15 N031 N030 1500
Rf2 Vdet3 N026 47000
Rg2 N026 0 2490
V5 N033 0 -14
V6 N027 0 14
Vamc2 N028 0 0
XU10 N034 N035 N034 opamp Aol=100K GBW=10Meg ;pnba invin)noninvin)out
R16 N035 N030 1500
C5 N035 0 100n
R17 Vmonitor3 N034 50
R18 N031 N013 60400
C6 N031 0 100n
;dc Vamc1200 -0.025 0.025 0.01
.ac dec 5 10 100k
;tran 15m

* LTspice schematic (.asc)
Version 4
SHEET 1 1312 2848
WIRE -336 -1408 -336 -1424
WIRE -48 -1344 -128 -1344
WIRE 144 -1344 32 -1344
WIRE 176 -1344 144 -1344
WIRE 288 -1344 256 -1344
WIRE -128 -1296 -128 -1344
WIRE -336 -1280 -336 -1328
WIRE -368 -1264 -656 -1264
WIRE -656 -1232 -656 -1264
WIRE -368 -1232 -464 -1232
WIRE -464 -1216 -464 -1232
WIRE 144 -1216 144 -1344
WIRE 176 -1216 144 -1216
WIRE 288 -1200 288 -1344
WIRE 288 -1200 240 -1200
WIRE 416 -1200 288 -1200
WIRE -112 -1184 -192 -1184
WIRE -48 -1184 -112 -1184
WIRE 96 -1184 32 -1184
WIRE 176 -1184 96 -1184
WIRE -368 -1136 -464 -1136
WIRE -656 -1104 -656 -1152
WIRE -368 -1104 -656 -1104
WIRE -656 -1072 -656 -1104
WIRE -336 -1072 -336 -1088
WIRE 384 -1072 256 -1072
WIRE 256 -1024 256 -1072
WIRE 288 -1024 256 -1024
WIRE 384 -1008 384 -1072
WIRE 384 -1008 352 -1008
WIRE 464 -1008 384 -1008
WIRE 640 -1008 544 -1008
WIRE -112 -992 -112 -1184
WIRE 144 -992 -112 -992
WIRE 256 -992 224 -992
WIRE 288 -992 256 -992
WIRE -336 -976 -336 -992
WIRE 256 -960 256 -992
WIRE 256 -880 256 -896
WIRE -560 -784 -656 -784
WIRE -432 -784 -480 -784
WIRE -304 -784 -352 -784
WIRE -272 -784 -304 -784
WIRE -160 -784 -192 -784
WIRE -64 -784 -160 -784
WIRE 96 -784 96 -1184
WIRE 96 -784 16 -784
WIRE -656 -736 -656 -784
WIRE 96 -736 96 -784
WIRE -304 -656 -304 -784
WIRE -272 -656 -304 -656
WIRE -160 -640 -160 -784
WIRE -160 -640 -208 -640
WIRE 96 -640 96 -672
WIRE -512 -624 -608 -624
WIRE -272 -624 -432 -624
WIRE -608 -608 -608 -624
WIRE -608 -512 -608 -528
WIRE -320 -400 -320 -416
WIRE -32 -336 -112 -336
WIRE 160 -336 48 -336
WIRE 192 -336 160 -336
WIRE 304 -336 272 -336
WIRE -112 -288 -112 -336
WIRE -320 -272 -320 -320
WIRE -352 -256 -640 -256
WIRE -640 -224 -640 -256
WIRE -352 -224 -448 -224
WIRE -448 -208 -448 -224
WIRE 160 -208 160 -336
WIRE 192 -208 160 -208
WIRE 304 -192 304 -336
WIRE 304 -192 256 -192
WIRE 432 -192 304 -192
WIRE -96 -176 -176 -176
WIRE -32 -176 -96 -176
WIRE 128 -176 48 -176
WIRE 192 -176 128 -176
WIRE -352 -128 -448 -128
WIRE -640 -96 -640 -144
WIRE -352 -96 -640 -96
WIRE -640 -64 -640 -96
WIRE -320 -64 -320 -80
WIRE -160 16 -160 -640
WIRE -32 16 -160 16
WIRE 128 16 128 -176
WIRE 128 16 48 16
WIRE -320 32 -320 16
WIRE 128 64 128 16
WIRE 128 160 128 128
WIRE 400 288 272 288
WIRE 272 336 272 288
WIRE 304 336 272 336
WIRE 400 352 400 288
WIRE 400 352 368 352
WIRE 480 352 400 352
WIRE 656 352 560 352
WIRE -96 368 -96 -176
WIRE 160 368 -96 368
WIRE 272 368 240 368
WIRE 304 368 272 368
WIRE 272 400 272 368
WIRE 272 480 272 464
WIRE -336 544 -336 528
WIRE -48 608 -128 608
WIRE 144 608 32 608
WIRE 176 608 144 608
WIRE 288 608 256 608
WIRE -128 656 -128 608
WIRE -336 672 -336 624
WIRE -368 688 -656 688
WIRE -656 720 -656 688
WIRE -368 720 -464 720
WIRE -464 736 -464 720
WIRE 144 736 144 608
WIRE 176 736 144 736
WIRE 288 752 288 608
WIRE 288 752 240 752
WIRE 416 752 288 752
WIRE -112 768 -192 768
WIRE -48 768 -112 768
WIRE 112 768 32 768
WIRE 176 768 112 768
WIRE -368 816 -464 816
WIRE -656 848 -656 800
WIRE -368 848 -656 848
WIRE -656 880 -656 848
WIRE -336 880 -336 864
WIRE -160 960 -160 16
WIRE -160 960 -176 960
WIRE -48 960 -160 960
WIRE 112 960 112 768
WIRE 112 960 32 960
WIRE -336 976 -336 960
WIRE 112 1008 112 960
WIRE 112 1104 112 1072
WIRE 384 1232 256 1232
WIRE 256 1280 256 1232
WIRE 288 1280 256 1280
WIRE 384 1296 384 1232
WIRE 384 1296 352 1296
WIRE 464 1296 384 1296
WIRE 640 1296 544 1296
WIRE -112 1312 -112 768
WIRE 144 1312 -112 1312
WIRE 256 1312 224 1312
WIRE 288 1312 256 1312
WIRE 256 1344 256 1312
WIRE 256 1424 256 1408
FLAG -608 -512 0
FLAG -656 -736 0
FLAG 96 -640 0
FLAG -128 -1296 0
FLAG -336 -976 0
FLAG -336 -1424 0
FLAG -256 -1120 0
FLAG -656 -1072 0
FLAG 416 -1200 Vdet
FLAG 640 -1008 Vmonitor
FLAG 256 -880 0
FLAG -112 -288 0
FLAG -320 32 0
FLAG -320 -416 0
FLAG -240 -112 0
FLAG -640 -64 0
FLAG 432 -192 Vdet2
FLAG 656 352 Vmonitor2
FLAG 272 480 0
FLAG 128 160 0
FLAG -128 656 0
FLAG -336 976 0
FLAG -336 528 0
FLAG -256 832 0
FLAG -656 880 0
FLAG 416 752 Vdet3
FLAG 640 1296 Vmonitor3
FLAG 256 1424 0
FLAG 112 1104 0
SYMBOL OpAmps\\AD8421 -336 -1184 R0
SYMATTR InstName U1
SYMBOL res -480 -1232 R0
SYMATTR InstName R1
SYMATTR Value 2490
SYMBOL OpAmps\\opamp -240 -704 R0
SYMATTR InstName U2
SYMBOL voltage -608 -624 R0
SYMATTR InstName Vref
SYMATTR Value 5
SYMBOL res -416 -640 R90
SYMATTR InstName R2
SYMATTR Value 620
SYMBOL res -176 -800 R90
SYMATTR InstName R3
SYMATTR Value 620
SYMBOL res -336 -800 R90
SYMATTR InstName R4
SYMATTR Value 14k
SYMBOL res -464 -800 R90
SYMATTR InstName TrimVref
SYMATTR Value 2256.4
SYMBOL OpAmps\\opamp 208 -1264 R0
SYMATTR InstName U3
SYMBOL res 48 -1200 R90
SYMATTR InstName R6
SYMATTR Value 1500
SYMBOL res 272 -1360 R90
SYMATTR InstName Rf
SYMATTR Value 47000
SYMBOL res 48 -1360 R90
SYMATTR InstName Rg
SYMATTR Value 2490
SYMBOL res 32 -800 R90
SYMATTR InstName R7
SYMATTR Value 60400
SYMBOL cap 80 -736 R0
SYMATTR InstName C1
SYMATTR Value 100n
SYMBOL voltage -336 -1088 R0
SYMATTR InstName V2
SYMATTR Value -14
SYMBOL voltage -336 -1312 R180
SYMATTR InstName V3
SYMATTR Value 14
SYMBOL voltage -656 -1248 R0
SYMATTR InstName Vamc1200
SYMATTR Value2 AC 1
SYMATTR Value 0
SYMBOL OpAmps\\opamp 320 -1072 R0
SYMATTR InstName U4
SYMBOL res 240 -1008 R90
SYMATTR InstName R5
SYMATTR Value 1500
SYMBOL cap 240 -960 R0
SYMATTR InstName C2
SYMATTR Value 100n
SYMBOL res 560 -1024 R90
SYMATTR InstName R8
SYMATTR Value 50
SYMBOL OpAmps\\AD8421 -320 -176 R0
SYMATTR InstName U5
SYMBOL res -464 -224 R0
SYMATTR InstName R9
SYMATTR Value 2490
SYMBOL OpAmps\\opamp 224 -256 R0
SYMATTR InstName U6
SYMBOL res 64 -192 R90
SYMATTR InstName R10
SYMATTR Value 1500
SYMBOL res 288 -352 R90
SYMATTR InstName Rf1
SYMATTR Value 47000
SYMBOL res 64 -352 R90
SYMATTR InstName Rg1
SYMATTR Value 2490
SYMBOL voltage -320 -80 R0
SYMATTR InstName V1
SYMATTR Value -14
SYMBOL voltage -320 -304 R180
SYMATTR InstName V4
SYMATTR Value 14
SYMBOL voltage -640 -240 R0
SYMATTR InstName Vamc1
SYMATTR Value PULSE(-0.025 0.025 1m 1n 1n 10m)
SYMBOL OpAmps\\opamp 336 288 R0
SYMATTR InstName U7
SYMBOL res 256 352 R90
SYMATTR InstName R11
SYMATTR Value 1500
SYMBOL cap 256 400 R0
SYMATTR InstName C3
SYMATTR Value 100n
SYMBOL res 576 336 R90
SYMATTR InstName R12
SYMATTR Value 50
SYMBOL res 64 0 R90
SYMATTR InstName R13
SYMATTR Value 60400
SYMBOL cap 112 64 R0
SYMATTR InstName C4
SYMATTR Value 100n
SYMBOL OpAmps\\AD8421 -336 768 R0
SYMATTR InstName U8
SYMBOL res -480 720 R0
SYMATTR InstName R14
SYMATTR Value 2490
SYMBOL OpAmps\\opamp 208 688 R0
SYMATTR InstName U9
SYMBOL res 48 752 R90
SYMATTR InstName R15
SYMATTR Value 1500
SYMBOL res 272 592 R90
SYMATTR InstName Rf2
SYMATTR Value 47000
SYMBOL res 48 592 R90
SYMATTR InstName Rg2
SYMATTR Value 2490
SYMBOL voltage -336 864 R0
SYMATTR InstName V5
SYMATTR Value -14
SYMBOL voltage -336 640 R180
SYMATTR InstName V6
SYMATTR Value 14
SYMBOL voltage -656 704 R0
SYMATTR InstName Vamc2
SYMATTR Value 0
SYMBOL OpAmps\\opamp 320 1232 R0
SYMATTR InstName U10
SYMBOL res 240 1296 R90
SYMATTR InstName R16
SYMATTR Value 1500
SYMBOL cap 240 1344 R0
SYMATTR InstName C5
SYMATTR Value 100n
SYMBOL res 560 1280 R90
SYMATTR InstName R17
SYMATTR Value 50
SYMBOL res 48 944 R90
SYMATTR InstName R18
SYMATTR Value 60400
SYMBOL cap 96 1008 R0
SYMATTR InstName C6
SYMATTR Value 100n