Version 4
SHEET 1 1056 680
WIRE -112 -80 -224 -80
WIRE 16 -80 -32 -80
WIRE 64 -80 16 -80
WIRE 192 -80 64 -80
WIRE 432 -80 256 -80
WIRE -224 -48 -224 -80
WIRE -224 48 -224 32
WIRE 304 96 304 64
WIRE -176 112 -224 112
WIRE -112 112 -176 112
WIRE 16 112 16 -80
WIRE 16 112 -32 112
WIRE 48 112 16 112
WIRE 160 112 128 112
WIRE 272 112 160 112
WIRE 432 128 432 -80
WIRE 432 128 336 128
WIRE 496 128 432 128
WIRE 592 128 496 128
WIRE 272 144 256 144
WIRE 160 160 160 112
WIRE 592 160 592 128
WIRE -368 176 -368 144
WIRE -224 176 -224 112
WIRE 304 192 304 160
WIRE 352 192 304 192
WIRE 256 224 256 144
WIRE 432 224 432 128
WIRE 432 224 256 224
WIRE -448 288 -448 272
WIRE -368 288 -368 256
WIRE -224 288 -224 256
WIRE 160 288 160 224
WIRE 592 288 592 240
FLAG 160 288 0
FLAG 592 288 0
FLAG -224 288 0
FLAG -368 288 0
FLAG -368 144 V+
FLAG -448 288 0
FLAG -448 272 V-
FLAG 352 192 V+
FLAG 304 64 V-
FLAG -224 48 0
FLAG 592 128 out
DATAFLAG 496 128 "round($*1k)/1k"
DATAFLAG -176 112 "round($*1k)/1k"
DATAFLAG 64 -80 "round($*1k)/1k"
SYMBOL cap 144 160 R0
SYMATTR InstName C1
SYMATTR Value 10n
SYMBOL cap 256 -96 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C2
SYMATTR Value {C2}
SYMBOL voltage -224 160 R0
WINDOW 123 26 121 Left 0
WINDOW 39 0 0 Left 0
WINDOW 3 30 91 Left 0
SYMATTR Value2 AC 2
SYMATTR Value 0
SYMATTR InstName V1
SYMBOL voltage -368 160 R0
WINDOW 3 40 94 Left 0
WINDOW 123 24 132 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value 3.3
SYMATTR InstName V2
SYMBOL Opamps\\LTC6084 304 128 M180
SYMATTR InstName U3
SYMBOL voltage -224 -64 R0
WINDOW 123 24 132 Left 0
WINDOW 39 0 0 Left 0
WINDOW 3 36 80 Left 0
SYMATTR Value 2.5
SYMATTR InstName V3
SYMBOL Misc\\EuropeanResistor 576 144 R0
SYMATTR InstName R4
SYMATTR Value 10k
SYMBOL Misc\\EuropeanResistor -128 -64 R270
WINDOW 0 27 56 VTop 0
WINDOW 3 5 56 VBottom 0
SYMATTR InstName R3
SYMATTR Value 20k
SYMBOL Misc\\EuropeanResistor -128 128 R270
WINDOW 0 27 56 VTop 0
WINDOW 3 5 56 VBottom 0
SYMATTR InstName R2
SYMATTR Value 20k
SYMBOL Misc\\EuropeanResistor 32 128 R270
WINDOW 0 27 56 VTop 0
WINDOW 3 5 56 VBottom 0
SYMATTR InstName R1
SYMATTR Value 10k
TEXT -392 -144 Left 0 !.ac dec 100 10 1E6
TEXT -264 -240 Left 0 !.measure fg find freq when mag(V(out))=1/sqrt(2)
TEXT -128 -176 Left 0 !.step param C2 1n 33n 1n