* SPICE netlist
Md1 vgatep 0 vs vs NMOS-SH l=1u w=10u
VSS 0 -VSS 1.5
Md2 vout vid2 vs vs NMOS-SH l=1u w=10u
Mtail vs vgatebias -VSS -VSS NMOS-SH l=1u w=10u
Mp2 vout vgatep VDD VDD PMOS-SH l=1u w=10u
Mp1 vgatep vgatep VDD VDD PMOS-SH l=1u w=10u
Mbias vgatebias vgatebias -VSS -VSS NMOS-SH l=1u w=10u
R1 VDD vgatebias 20k
VDD VDD 0 1.5
VCM vin 0 SINE(0 1m 1k) AC 1
C1 vout 0 0.5p
R2 vout vid2 10Meg
R3 vid2 vin 2.5Meg
;.dc VCM -500m 500m 10u
.op
;ac oct 100 10 1000MEG
.tran 2m

* LTspice schematic (.asc)
Version 4
SHEET 1 1744 688
WIRE -520 -344 -744 -344
WIRE -296 -344 -520 -344
WIRE -216 -344 -296 -344
WIRE -104 -344 -216 -344
WIRE 136 -344 -104 -344
WIRE 200 -344 136 -344
WIRE -216 -280 -216 -344
WIRE 136 -280 136 -344
WIRE -88 -264 -168 -264
WIRE -24 -264 -88 -264
WIRE 88 -264 -24 -264
WIRE -296 -232 -296 -344
WIRE -216 -232 -296 -232
WIRE 200 -232 200 -344
WIRE 200 -232 136 -232
WIRE 424 -216 360 -216
WIRE 568 -216 504 -216
WIRE 616 -216 568 -216
WIRE 792 -216 696 -216
WIRE 872 -216 792 -216
WIRE -744 -200 -744 -344
WIRE -520 -152 -520 -344
WIRE 136 -120 136 -184
WIRE 216 -120 136 -120
WIRE 360 -120 360 -216
WIRE 360 -120 216 -120
WIRE -216 -104 -216 -184
WIRE -88 -104 -88 -264
WIRE -88 -104 -216 -104
WIRE 360 -104 360 -120
WIRE 872 -104 872 -216
WIRE -216 -56 -216 -104
WIRE 136 -56 136 -120
WIRE -744 -24 -744 -120
WIRE -744 -24 -872 -24
WIRE -136 -8 -216 -8
WIRE 136 -8 72 -8
WIRE 360 -8 360 -40
WIRE -264 24 -360 24
WIRE 232 24 184 24
WIRE 568 24 568 -216
WIRE 568 24 232 24
WIRE 872 24 872 -24
WIRE -872 56 -872 -24
WIRE -360 72 -360 24
WIRE -216 104 -216 40
WIRE -136 104 -136 -8
WIRE -136 104 -216 104
WIRE -56 104 -136 104
WIRE -24 104 -56 104
WIRE 72 104 72 -8
WIRE 72 104 -24 104
WIRE 136 104 136 40
WIRE 136 104 72 104
WIRE -520 120 -520 -72
WIRE -456 120 -520 120
WIRE -408 120 -456 120
WIRE -744 152 -744 -24
WIRE -520 152 -520 120
WIRE -56 152 -56 104
WIRE -520 200 -600 200
WIRE 8 200 -56 200
WIRE -408 232 -408 120
WIRE -408 232 -472 232
WIRE -104 232 -408 232
WIRE -744 344 -744 232
WIRE -600 344 -600 200
WIRE -600 344 -744 344
WIRE -520 344 -520 248
WIRE -520 344 -600 344
WIRE -200 344 -520 344
WIRE -56 344 -56 248
WIRE -56 344 -200 344
WIRE 8 344 8 200
WIRE 8 344 -56 344
FLAG -872 56 0
FLAG 872 24 0
FLAG 232 24 vid2
FLAG 360 -8 0
FLAG 216 -120 vout
FLAG -24 104 vs
FLAG -456 120 vgatebias
FLAG -24 -264 vgatep
FLAG -104 -344 VDD
FLAG -200 344 -VSS
FLAG -360 72 0
FLAG 792 -216 vin
DATAFLAG -112 160 ""
DATAFLAG 16 304 ""
DATAFLAG -640 176 ""
DATAFLAG -544 384 ""
DATAFLAG 112 64 ""
SYMBOL nmos4 -264 -56 R0
SYMATTR Value2 l=1u w=10u
SYMATTR InstName Md1
SYMATTR Value NMOS-SH
SYMBOL voltage -744 136 R0
SYMATTR InstName VSS
SYMATTR Value 1.5
SYMBOL nmos4 184 -56 M0
SYMATTR Value2 l=1u w=10u
SYMATTR InstName Md2
SYMATTR Value NMOS-SH
SYMBOL nmos4 -104 152 R0
SYMATTR Value2 l=1u w=10u
SYMATTR InstName Mtail
SYMATTR Value NMOS-SH
SYMBOL pmos4 88 -184 M180
SYMATTR Value2 l=1u w=10u
SYMATTR InstName Mp2
SYMATTR Value PMOS-SH
SYMBOL pmos4 -168 -184 R180
SYMATTR Value2 l=1u w=10u
SYMATTR InstName Mp1
SYMATTR Value PMOS-SH
SYMBOL nmos4 -472 152 M0
SYMATTR Value2 l=1u w=10u
SYMATTR InstName Mbias
SYMATTR Value NMOS-SH
SYMBOL res -536 -168 R0
SYMATTR InstName R1
SYMATTR Value 20k
SYMBOL voltage -744 -216 R0
SYMATTR InstName VDD
SYMATTR Value 1.5
SYMBOL voltage 872 -120 R0
SYMATTR Value2 AC 1
SYMATTR InstName VCM
SYMATTR Value SINE(0 1m 1k)
SYMBOL cap 344 -104 R0
SYMATTR InstName C1
SYMATTR Value 0.5p
SYMBOL res 408 -200 R270
SYMATTR InstName R2
SYMATTR Value 10Meg
SYMBOL res 600 -200 R270
SYMATTR InstName R3
SYMATTR Value 2.5Meg