* SPICE netlist
Vin Vin 0 PWL(0 15 10u 15 11u 500)
V1 N007 0 2.5
Rupper Vout N006 10k
Rlower N006 0 10k
R3 Vout 0 50
V3 V+ 0 12
V4 0 V- 12
XE3 0 N003 v- v+ +ve1 level1 Avol=10 GBW=10Meg Vos=0 En=0 Enk=0 In=0 Ink=0 Rin=500Meg ;pnba In+)In-)V+)V-)OUT
R4 +ve1 N003 10k
R5 N003 -ve1 10k
XE1 N007 N006 V+ V- N004 level1 Avol=100 GBW=10Meg Vos=0 En=0 Enk=0 In=0 Ink=0 Rin=500Meg ;pnba In+)In-)V+)V-)OUT
Cf N006 N005 100n
Rf N005 N004 100
XE4 N004 0 V+ V- -ve1 level1 Avol=100 GBW=10Meg Vos=0 En=0 Enk=0 In=0 Ink=0 Rin=500Meg ;pnba In+)In-)V+)V-)OUT
XX2 Vin 0 V+ V- N001 level1 Avol=0.05 GBW=10Meg Vos=0 En=0 Enk=0 In=0 Ink=0 Rin=500Meg ;pnba In+)In-)V+)V-)OUT
XX3 N001 +ve1 V+ V- N002 level1 Avol=1 GBW=10Meg Vos=0 En=0 Enk=0 In=0 Ink=0 Rin=500Meg ;pnba In+)In-)V+)V-)OUT
R1 Vout N002 1
.tran 0 1 0 500n uic
.options numdgt = 7
.options plotwinsize = 0

* LTspice schematic (.asc)
Version 4
SHEET 1 1824 544
WIRE -912 -224 -912 -272
WIRE -736 -224 -912 -224
WIRE -448 -208 -672 -208
WIRE -736 -192 -768 -192
WIRE -336 -192 -384 -192
WIRE -64 -192 -256 -192
WIRE 80 -192 80 -272
WIRE 80 -192 -64 -192
WIRE -448 -176 -480 -176
WIRE -768 -160 -768 -192
WIRE 800 -112 752 -112
WIRE 912 -112 880 -112
WIRE -576 -96 -576 -128
WIRE -400 -48 -464 -48
WIRE -272 -48 -320 -48
WIRE -160 -48 -208 -48
WIRE -64 -48 -64 -192
WIRE -912 0 -912 -224
WIRE 80 0 80 -192
WIRE 272 0 272 -96
WIRE 416 0 416 -96
WIRE -592 16 -592 -32
WIRE 816 16 816 0
WIRE -320 32 -400 32
WIRE 640 32 576 32
WIRE 752 32 752 -112
WIRE 752 32 720 32
WIRE 784 32 752 32
WIRE -160 48 -160 -48
WIRE -160 48 -288 48
WIRE -64 48 -64 32
WIRE -64 48 -160 48
WIRE 912 48 912 -112
WIRE 912 48 848 48
WIRE -560 64 -560 -32
WIRE -464 64 -464 -48
WIRE -464 64 -560 64
WIRE -352 64 -464 64
WIRE 784 64 768 64
WIRE -224 80 -288 80
WIRE -320 96 -400 96
WIRE 816 96 816 80
WIRE -224 112 -224 80
WIRE -64 112 -64 48
WIRE 768 112 768 64
WIRE 272 192 272 80
WIRE 416 192 416 80
WIRE -912 240 -912 80
WIRE -224 240 -224 192
WIRE -224 240 -912 240
WIRE -64 240 -64 192
WIRE -64 240 -224 240
WIRE 80 240 80 80
WIRE 80 240 -64 240
WIRE -224 272 -224 240
FLAG -400 32 V+
FLAG -400 96 V-
FLAG 272 192 0
FLAG 416 192 0
FLAG 272 -96 V+
FLAG 416 -96 V-
FLAG -224 272 0
FLAG 768 112 0
FLAG 912 48 +ve1
FLAG 816 0 v-
FLAG 816 96 v+
FLAG 576 32 -ve1
FLAG -592 16 0
FLAG -608 -64 V+
FLAG -544 -64 V-
FLAG -576 -128 -ve1
FLAG -704 -176 V+
FLAG -704 -240 V-
FLAG -768 -160 0
FLAG -416 -160 V+
FLAG -416 -224 V-
FLAG -480 -176 +ve1
FLAG 80 -272 Vout
FLAG -912 -272 Vin
SYMBOL voltage -912 -16 R0
SYMATTR InstName Vin
SYMATTR Value PWL(0 15 10u 15 11u 500)
SYMBOL voltage -224 96 R0
SYMATTR InstName V1
SYMATTR Value 2.5
SYMBOL res -80 -64 R0
SYMATTR InstName Rupper
SYMATTR Value 10k
SYMBOL res -80 96 R0
SYMATTR InstName Rlower
SYMATTR Value 10k
SYMBOL res 64 -16 R0
SYMATTR InstName R3
SYMATTR Value 50
SYMBOL voltage 272 -16 R0
SYMATTR InstName V3
SYMATTR Value 12
SYMBOL voltage 416 96 R180
SYMATTR InstName V4
SYMATTR Value 12
SYMBOL OpAmps\\UniversalOpAmp1 816 48 R0
SYMATTR InstName E3
SYMATTR Value2 Avol=10 GBW=10Meg Vos=0
SYMBOL res 896 -128 R90
SYMATTR InstName R4
SYMATTR Value 10k
SYMBOL res 736 16 R90
SYMATTR InstName R5
SYMATTR Value 10k
SYMBOL OpAmps\\UniversalOpAmp1 -320 64 M0
SYMATTR InstName E1
SYMATTR Value2 Avol=100 GBW=10Meg Vos=0
SYMBOL cap -208 -64 R90
SYMATTR InstName Cf
SYMATTR Value 100n
SYMBOL res -304 -64 R90
SYMATTR InstName Rf
SYMATTR Value 100
SYMBOL OpAmps\\UniversalOpAmp1 -576 -64 R270
SYMATTR InstName E4
SYMATTR Value2 Avol=100 GBW=10Meg Vos=0
SYMBOL OpAmps\\UniversalOpAmp1 -704 -208 M180
SYMATTR InstName X2
SYMATTR Value2 Avol=0.05 GBW=10Meg Vos=0
SYMBOL OpAmps\\UniversalOpAmp1 -416 -192 M180
SYMATTR InstName X3
SYMATTR Value2 Avol=1 GBW=10Meg Vos=0
SYMBOL res -240 -208 R90
SYMATTR InstName R1
SYMATTR Value 1