* SPICE netlist
V1 +V 0 5
I1 0 Z AC 1
V3 Z N002 0
V4 Z N003 0
R1 N003 0 10k
R2 N001 0 10k
R3 N003 N001 100
C1 N004 N001 35n
R5 N005 0 10k
R6 Y N005 100
C2 N006 N005 35n
V5 -V 0 -5
R4 Y 0 10k
V2 Y X AC 1
V6 offs 0 0
XU1 offs N001 +V -V N002 LTC6241 ;pnba IN+)IN-)VCC)VEE)OUT
XU2 offs N005 +V -V X LTC6241 ;pnba IN+)IN-)VCC)VEE)OUT
C3 N001 0 {CP}
C4 N005 0 {CP}
R7 N006 Y 20
R8 N004 N003 20
.ac dec 30 .1 10Meg
.param CP=10u
.STEP PARAM Cp LIST 1n 10n 100n 1u 10u

* LTspice schematic (.asc)
Version 4
SHEET 1 1136 768
WIRE 264 -368 264 -384
WIRE -24 -288 -24 -304
WIRE -248 -272 -328 -272
WIRE -168 -272 -248 -272
WIRE -56 -272 -168 -272
WIRE 168 -256 8 -256
WIRE 264 -256 264 -288
WIRE 264 -256 248 -256
WIRE 280 -256 264 -256
WIRE 312 -256 280 -256
WIRE 504 -256 392 -256
WIRE -248 -240 -248 -272
WIRE -56 -240 -88 -240
WIRE -568 -224 -568 -240
WIRE -328 -224 -328 -272
WIRE -24 -208 -24 -224
WIRE 504 -208 504 -256
WIRE 568 -208 504 -208
WIRE 568 -192 568 -208
WIRE -568 -128 -568 -144
WIRE -328 -128 -328 -160
WIRE -248 -128 -248 -160
WIRE -56 -128 -72 -128
WIRE 24 -128 8 -128
WIRE 120 -128 104 -128
WIRE 568 -96 568 -112
WIRE -568 -32 -568 -48
WIRE -456 -32 -456 -48
WIRE -168 -32 -168 -272
WIRE -72 -32 -72 -128
WIRE -72 -32 -168 -32
WIRE -40 -32 -72 -32
WIRE 120 -32 120 -128
WIRE 120 -32 40 -32
WIRE 504 -32 504 -208
WIRE 504 -32 120 -32
WIRE -568 64 -568 48
WIRE -456 64 -456 48
WIRE -24 112 -24 96
WIRE -248 128 -328 128
WIRE -168 128 -248 128
WIRE -56 128 -168 128
WIRE 232 144 8 144
WIRE 248 144 232 144
WIRE 360 144 328 144
WIRE 488 144 360 144
WIRE -248 160 -248 128
WIRE -56 160 -88 160
WIRE -328 176 -328 128
WIRE -24 192 -24 176
WIRE 488 192 488 144
WIRE 552 192 488 192
WIRE 552 208 552 192
WIRE -328 272 -328 240
WIRE -248 272 -248 240
WIRE -56 272 -72 272
WIRE 24 272 8 272
WIRE 120 272 104 272
WIRE 552 304 552 288
WIRE -168 368 -168 128
WIRE -72 368 -72 272
WIRE -72 368 -168 368
WIRE -40 368 -72 368
WIRE 120 368 120 272
WIRE 120 368 40 368
WIRE 488 368 488 192
WIRE 488 368 120 368
FLAG 264 -384 0
FLAG -456 64 0
FLAG -248 -128 0
FLAG 568 -96 0
FLAG -248 272 0
FLAG 232 144 X
FLAG 360 144 Y
FLAG -24 -304 +V
FLAG -456 -48 +V
FLAG -568 64 0
FLAG -568 -48 -V
FLAG -24 -208 -V
FLAG -24 96 +V
FLAG -24 192 -V
FLAG 552 304 0
FLAG 280 -256 Z
FLAG -88 -240 offs
FLAG -88 160 offs
FLAG -568 -128 0
FLAG -568 -240 offs
FLAG -328 -128 0
FLAG -328 272 0
SYMBOL voltage -456 -48 R0
SYMATTR InstName V1
SYMATTR Value 5
SYMBOL current 264 -368 R0
SYMATTR InstName AC
SYMATTR InstName I1
SYMATTR Value 1
SYMBOL voltage 264 -256 R90
SYMATTR InstName V3
SYMATTR Value 0
SYMBOL voltage 296 -256 R270
SYMATTR InstName V4
SYMATTR Value 0
SYMBOL res 552 -208 R0
SYMATTR InstName R1
SYMATTR Value 10k
SYMBOL res -264 -256 R0
SYMATTR InstName R2
SYMATTR Value 10k
SYMBOL res 56 -48 R90
SYMATTR InstName R3
SYMATTR Value 100
SYMBOL cap 8 -144 R90
SYMATTR InstName C1
SYMATTR Value 35n
SYMBOL res -264 144 R0
SYMATTR InstName R5
SYMATTR Value 10k
SYMBOL res 56 384 M270
SYMATTR InstName R6
SYMATTR Value 100
SYMBOL cap 8 288 M270
SYMATTR InstName C2
SYMATTR Value 35n
SYMBOL voltage -568 -48 R0
SYMATTR InstName V5
SYMATTR Value -5
SYMBOL res 536 192 R0
SYMATTR InstName R4
SYMATTR Value 10k
SYMBOL voltage 344 144 R90
SYMATTR InstName V2
SYMATTR Value 1
SYMATTR InstName AC
SYMBOL voltage -568 -240 R0
SYMATTR InstName V6
SYMATTR Value 0
SYMBOL Opamps\\LTC6241 -24 -256 R0
SYMATTR InstName U1
SYMBOL Opamps\\LTC6241 -24 144 R0
SYMATTR InstName U2
SYMBOL cap -344 -224 R0
SYMATTR InstName C3
SYMATTR Value {CP}
SYMBOL cap -344 176 R0
SYMATTR InstName C4
SYMATTR Value {CP}
SYMBOL res 8 288 R270
SYMATTR InstName R7
SYMATTR Value 20
SYMBOL res 8 -112 R270
SYMATTR InstName R8
SYMATTR Value 20