* SPICE netlist
V1 VCC 0 {vcc} Rser=0.1
V2 VEE 0 {-vcc} Rser=0.1
R1 N004 N003 2.2k
R2 N003 N002 1k
R3 N004 N009 1.58k
R4 0 N008 1.58k
C1 N009 N008 1n
C2 N008 0 1n
XU1 N008 N003 VCC VEE N004 OPA1678 ;pnba In+)In-)V+)V-)OUT
XU2 N011 N005 VCC VEE AGC OPA1678 ;pnba In+)In-)V+)V-)OUT
V3 N010 0 1.24
J1 N002 N007 0 J113
C6 AGC N005 10n
D1 N010 N011 BAS16HY
D2 N004 N005 BAS16HY
R6 N011 0 10k
R7 N004 OUT 499
R8 OUT 0 10
R9 N007 AGC 1k
R5 N001 0 300
R10 AGC N005 100k
R11 AGC N006 1k
C3 N006 N005 10n
.tran 5m uic
.param vcc=3.3

* LTspice schematic (.asc)
Version 4
SHEET 1 1616 800
WIRE -24 -384 -72 -384
WIRE 104 -384 56 -384
WIRE -776 -288 -776 -304
WIRE -600 -288 -600 -304
WIRE -72 -256 -72 -384
WIRE -72 -256 -296 -256
WIRE -24 -256 -72 -256
WIRE 184 -256 72 -256
WIRE 328 -256 264 -256
WIRE 456 -256 328 -256
WIRE 632 -256 536 -256
WIRE -776 -192 -776 -208
WIRE -600 -192 -600 -208
WIRE -360 -112 -392 -112
WIRE -248 -112 -296 -112
WIRE -136 -112 -168 -112
WIRE 8 -80 8 -208
WIRE 440 -32 440 -48
WIRE -392 -16 -392 -112
WIRE -280 -16 -392 -16
WIRE -136 -16 -136 -112
WIRE -136 -16 -200 -16
WIRE 328 -16 328 -256
WIRE 408 -16 328 -16
WIRE 632 0 632 -256
WIRE 632 0 472 0
WIRE 232 16 152 16
WIRE 328 16 232 16
WIRE 408 16 328 16
WIRE 440 48 440 32
WIRE 632 48 632 0
WIRE 728 48 632 48
WIRE -392 64 -392 -16
WIRE -344 64 -392 64
WIRE -136 64 -136 -16
WIRE -136 64 -280 64
WIRE 152 64 152 16
WIRE 232 64 232 16
WIRE 728 64 728 48
WIRE -600 128 -808 128
WIRE -392 128 -392 64
WIRE -392 128 -536 128
WIRE 328 144 328 16
WIRE 360 144 328 144
WIRE 488 144 424 144
WIRE 632 144 632 48
WIRE 632 144 568 144
WIRE 152 160 152 128
WIRE 232 160 232 144
WIRE 728 160 728 144
WIRE 808 160 728 160
WIRE -264 176 -264 160
WIRE -392 192 -392 128
WIRE -296 192 -392 192
WIRE 728 192 728 160
WIRE -136 208 -136 64
WIRE -136 208 -232 208
WIRE -40 208 -136 208
WIRE 8 208 8 0
WIRE 8 208 -40 208
WIRE -600 224 -728 224
WIRE -392 224 -536 224
WIRE -296 224 -392 224
WIRE -728 240 -728 224
WIRE -264 256 -264 240
WIRE 728 288 728 272
WIRE -392 320 -392 304
WIRE -728 336 -728 320
WIRE -808 400 -808 128
WIRE 632 400 632 144
WIRE 632 400 -808 400
FLAG -776 -192 0
FLAG -600 -192 0
FLAG -776 -304 VCC
FLAG -600 -304 VEE
FLAG 440 -48 VCC
FLAG 440 48 VEE
FLAG 232 160 0
FLAG 152 160 0
FLAG -296 -256 0
FLAG -264 160 VCC
FLAG -264 256 VEE
FLAG -728 336 0
FLAG -392 320 0
FLAG 728 288 0
FLAG -40 208 AGC
FLAG 808 160 OUT
SYMBOL voltage -776 -304 R0
SYMATTR Value {vcc}
SYMATTR SpiceLine Rser=0.1
SYMATTR InstName V1
SYMBOL voltage -600 -304 R0
SYMATTR SpiceLine Rser=0.1
SYMATTR InstName V2
SYMATTR Value {-vcc}
SYMBOL res 552 -272 R90
SYMATTR InstName R1
SYMATTR Value 2.2k
SYMBOL res 280 -272 R90
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL res 584 128 R90
SYMATTR InstName R3
SYMATTR Value 1.58k
SYMBOL res 216 160 M180
SYMATTR InstName R4
SYMATTR Value 1.58k
SYMBOL cap 424 128 R90
SYMATTR InstName C1
SYMATTR Value 1n
SYMBOL cap 136 64 R0
SYMATTR InstName C2
SYMATTR Value 1n
SYMBOL Opamps\\opamp2 440 -64 R0
SYMATTR InstName U1
SYMATTR Value OPA1678
SYMBOL Opamps\\opamp2 -264 144 R0
SYMATTR InstName U2
SYMATTR Value OPA1678
SYMBOL voltage -728 224 R0
SYMATTR InstName V3
SYMATTR Value 1.24
SYMBOL njf 72 -208 M270
SYMATTR InstName J1
SYMATTR Value J113
SYMBOL cap -280 48 R90
SYMATTR InstName C6
SYMATTR Value 10n
SYMBOL diode -600 240 R270
SYMATTR InstName D1
SYMATTR Value BAS16HY
SYMBOL diode -600 144 R270
SYMATTR InstName D2
SYMATTR Value BAS16HY
SYMBOL res -408 208 R0
SYMATTR InstName R6
SYMATTR Value 10k
SYMBOL res 712 48 R0
SYMATTR InstName R7
SYMATTR Value 499
SYMBOL res 712 176 R0
SYMATTR InstName R8
SYMATTR Value 10
SYMBOL res -8 -96 R0
SYMATTR InstName R9
SYMATTR Value 1k
SYMBOL res 72 -400 R90
SYMATTR InstName R5
SYMATTR Value 300
SYMBOL res -184 -32 R90
SYMATTR InstName R10
SYMATTR Value 100k
SYMBOL res -152 -128 R90
SYMATTR InstName R11
SYMATTR Value 1k
SYMBOL cap -296 -128 R90
SYMATTR InstName C3
SYMATTR Value 10n