Version 4
SHEET 1 960 680
WIRE 352 -80 192 -80
WIRE 624 -80 448 -80
WIRE 368 0 368 -32
WIRE 384 0 368 0
WIRE -192 16 -336 16
WIRE -48 16 -192 16
WIRE 192 16 192 -80
WIRE 192 16 -48 16
WIRE 384 32 384 0
WIRE 192 112 192 16
WIRE -336 128 -336 16
WIRE -192 128 -192 96
WIRE 160 128 -192 128
WIRE 624 128 624 -80
WIRE 384 144 384 112
WIRE 384 144 224 144
WIRE -48 160 -48 96
WIRE 160 160 -48 160
WIRE 384 176 384 144
WIRE -48 192 -48 160
WIRE -192 240 -192 128
WIRE -48 288 -48 256
WIRE 384 288 384 256
WIRE 384 288 -48 288
WIRE -336 320 -336 208
WIRE -192 320 -336 320
WIRE -48 320 -48 288
WIRE -192 400 -192 320
WIRE -128 400 -192 400
WIRE -48 400 -128 400
WIRE 192 400 192 176
WIRE 192 400 -48 400
WIRE 624 448 624 208
WIRE -128 480 -128 400
FLAG -128 480 0
FLAG 624 448 0
SYMBOL res -208 0 R0
SYMATTR InstName R1
SYMATTR Value 953000
SYMATTR SpiceLine tol=0.5
SYMBOL res -208 224 R0
SYMATTR InstName R2
SYMATTR Value 1000000
SYMATTR SpiceLine tol=0.1
SYMBOL res -64 0 R0
SYMATTR InstName R3
SYMATTR Value 2000000
SYMATTR SpiceLine tol=0.5
SYMBOL res -64 304 R0
SYMATTR InstName R4
SYMATTR Value 500000
SYMATTR SpiceLine tol=1
SYMBOL res 368 160 R0
SYMATTR InstName R5
SYMATTR Value 10000000
SYMATTR SpiceLine tol=0.5
SYMBOL res 368 16 R0
SYMATTR InstName R6
SYMATTR Value 1000000
SYMATTR SpiceLine tol=0.1
SYMBOL pmos 448 -32 M270
SYMATTR InstName M1
SYMATTR Value Si7465DP
SYMBOL voltage -336 112 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 20
SYMBOL Opamps\\LT1495 192 80 R0
SYMATTR InstName U3
SYMBOL res 608 112 R0
SYMATTR InstName R7
SYMATTR Value 100
SYMBOL References\\LT1634-5 -48 224 R0
SYMATTR InstName U1
TEXT -392 376 Left 2 !.dc V1 20 0 0.001