* SPICE netlist
XU1 0 N004 Vcc Vee N005 level1 Avol=1Meg GBW=10Meg Vos=0 En=0 Enk=0 In=0 Ink=0 Rin=500Meg ;pnba In+)In-)V+)V-)OUT
XU2 0 N006 Vcc Vee N003 level1 Avol=1Meg GBW=10Meg Vos=0 En=0 Enk=0 In=0 Ink=0 Rin=500Meg ;pnba In+)In-)V+)V-)OUT
XU3 0 N008 Vcc Vee N009 level1 Avol=1Meg GBW=10Meg Vos=0 En=0 Enk=0 In=0 Ink=0 Rin=500Meg ;pnba In+)In-)V+)V-)OUT
R1 N004 N003 2.2k
R2 N009 N008 7.5k
R11 P001 N006 50k
R4 N006 N002 10k
R5 N004 N009 2.2k
R6 N008 N010 7.5k
R7 N005 N004 2.2k
R8 Vo N005 1k
C1 N003 P001 1200n
C2 N010 N002 200n
C3 0 Vo 1m
V1 Vset 0 PWL(0 1 2 -1 4 0 6 -1 8 0)
V2 Vcc 0 15V
V3 Vee 0 -15V
XU4 N007 N001 Vcc Vee N002 level1 Avol=1Meg GBW=10Meg Vos=0 En=0 Enk=0 In=0 Ink=0 Rin=500Meg ;pnba In+)In-)V+)V-)OUT
R3 N002 N001 4.7k
R9 N001 Vo 4.7k
R10 N007 Vset 4.7k
R12 0 N007 4.7k
.tran 10

* LTspice schematic (.asc)
Version 4
SHEET 1 1712 1008
WIRE 776 -504 -792 -504
WIRE -792 -248 -792 -504
WIRE -696 -248 -792 -248
WIRE -568 -248 -616 -248
WIRE -424 -248 -488 -248
WIRE 264 -232 136 -232
WIRE 456 -216 392 -216
WIRE 584 -216 536 -216
WIRE -616 -136 -616 -248
WIRE -568 -136 -616 -136
WIRE -424 -120 -424 -248
WIRE -424 -120 -504 -120
WIRE -216 -120 -424 -120
WIRE -120 -120 -216 -120
WIRE -8 -120 -8 -232
WIRE -8 -120 -40 -120
WIRE 104 -120 -8 -120
WIRE -744 -104 -856 -104
WIRE -632 -104 -664 -104
WIRE -568 -104 -632 -104
WIRE 264 -104 264 -232
WIRE 264 -104 168 -104
WIRE 296 -104 264 -104
WIRE 392 -104 392 -216
WIRE 392 -104 376 -104
WIRE 456 -104 392 -104
WIRE 104 -88 56 -88
WIRE 584 -88 584 -216
WIRE 584 -88 520 -88
WIRE 664 -88 584 -88
WIRE 776 -88 776 -504
WIRE 776 -88 744 -88
WIRE 856 -88 776 -88
WIRE 456 -72 424 -72
WIRE 56 -56 56 -88
WIRE 424 -56 424 -72
WIRE -632 -40 -632 -104
WIRE 776 -40 776 -88
WIRE 40 24 8 24
WIRE 248 24 120 24
WIRE -216 104 -216 -120
WIRE -200 104 -216 104
WIRE -104 104 -136 104
WIRE 8 104 8 24
WIRE 8 104 -24 104
WIRE 104 104 8 104
WIRE 248 120 248 24
WIRE 248 120 168 120
WIRE 296 120 248 120
WIRE 392 120 392 -104
WIRE 392 120 376 120
WIRE 104 136 72 136
WIRE 72 152 72 136
FLAG 136 504 0
FLAG 344 504 0
FLAG 136 424 Vcc
FLAG 344 424 Vee
FLAG 136 152 Vee
FLAG 136 -72 Vee
FLAG 488 -56 Vee
FLAG 136 88 Vcc
FLAG 136 -136 Vcc
FLAG 488 -120 Vcc
FLAG 776 24 0
FLAG -296 504 0
FLAG 72 152 0
FLAG 56 -56 0
FLAG 424 -56 0
FLAG -536 -88 Vee
FLAG -536 -152 Vcc
FLAG -632 40 0
FLAG -296 424 Vset
FLAG -856 -104 Vset
FLAG 856 -88 Vo
IOPIN 640 192 Out
SYMBOL OpAmps\\UniversalOpamp 488 -88 R0
SYMATTR InstName U1
SYMBOL OpAmps\\UniversalOpamp 136 -104 R0
SYMATTR InstName U2
SYMBOL OpAmps\\UniversalOpamp 136 120 R0
SYMATTR InstName U3
SYMBOL res 392 -120 R90
SYMATTR InstName R1
SYMATTR Value 2.2k
SYMBOL res 136 8 R90
SYMATTR InstName R2
SYMATTR Value 7.5k
SYMBOL res 88 -248 R90
SYMATTR InstName R11
SYMATTR Value 50k
SYMBOL res -24 -136 R90
SYMATTR InstName R4
SYMATTR Value 10k
SYMBOL res 392 104 R90
SYMATTR InstName R5
SYMATTR Value 2.2k
SYMBOL res -8 88 R90
SYMATTR InstName R6
SYMATTR Value 7.5k
SYMBOL res 552 -232 R90
SYMATTR InstName R7
SYMATTR Value 2.2k
SYMBOL res 760 -104 R90
SYMATTR InstName R8
SYMATTR Value 1k
SYMBOL cap 136 -248 R90
SYMATTR InstName C1
SYMATTR Value 1200n
SYMBOL cap -136 88 R90
SYMATTR InstName C2
SYMATTR Value 200n
SYMBOL cap 792 24 R180
SYMATTR InstName C3
SYMATTR Value 1m
SYMBOL voltage -296 408 R0
SYMATTR InstName V1
SYMATTR Value PWL(0 1 2 -1 4 0 6 -1 8 0)
SYMBOL voltage 136 408 R0
SYMATTR InstName V2
SYMATTR Value 15V
SYMBOL voltage 344 408 R0
SYMATTR InstName V3
SYMATTR Value -15V
SYMBOL OpAmps\\UniversalOpamp -536 -120 R0
SYMATTR InstName U4
SYMBOL res -472 -264 R90
SYMATTR InstName R3
SYMATTR Value 4.7k
SYMBOL res -600 -264 R90
SYMATTR InstName R9
SYMATTR Value 4.7k
SYMBOL res -648 -120 R90
SYMATTR InstName R10
SYMATTR Value 4.7k
SYMBOL res -616 56 R180
SYMATTR InstName R12
SYMATTR Value 4.7k