* SPICE netlist
VCOM_1 Vin1 N003 1V
VDD N001 0 1.8
EVDIFF_2 N004 0 N003 0 -1
VCOM_2 Vin2 N004 1V
VDIFF_1 N003 0 PULSE(0 200u 1m 10m 0 10s) AC 200u
M1 N002 Vin1 VS 0 nmos_custom
M2 Vout Vin2 VS 0 nmos_custom
M3 N001 N002 Vout N001 pmos_custom
M4 N001 N002 N002 N001 pmos_custom
M5 VS VG_mirror 0 0 SQJ910AEP_Q2
M6 VG_mirror VG_mirror 0 0 SQJ910AEP_Q2
R1 VG_mirror N005 1k
V1 N005 0 2.10179
C1 0 Vout 1p
.dc VDIFF_1 -0.2m 0.2m 1n

* LTspice schematic (.asc)
Version 4.1
SHEET 1 960 864
WIRE 112 -432 -336 -432
WIRE 224 -432 112 -432
WIRE 336 -432 304 -432
WIRE 336 -416 336 -432
WIRE -336 -400 -336 -432
WIRE -336 -400 -400 -400
WIRE 112 -400 112 -432
WIRE 176 -400 112 -400
WIRE -336 -384 -336 -400
WIRE 112 -384 112 -400
WIRE -400 -336 -400 -400
WIRE -336 -336 -400 -336
WIRE 176 -336 176 -400
WIRE 176 -336 112 -336
WIRE -240 -304 -288 -304
WIRE 64 -304 -240 -304
WIRE -336 -240 -336 -288
WIRE -240 -240 -240 -304
WIRE -240 -240 -336 -240
WIRE 112 -160 112 -288
WIRE 224 -160 112 -160
WIRE 352 -160 224 -160
WIRE 480 -160 416 -160
WIRE -336 -144 -336 -240
WIRE 112 -144 112 -160
WIRE 480 -112 480 -160
WIRE -112 -96 -336 -96
WIRE 112 -96 -112 -96
WIRE -112 -80 -112 -96
WIRE -384 -64 -448 -64
WIRE 240 -64 160 -64
WIRE 256 -64 240 -64
WIRE -448 -32 -448 -64
WIRE -336 -16 -336 -48
WIRE -112 -16 -336 -16
WIRE 112 -16 112 -48
WIRE 112 -16 -112 -16
WIRE -448 64 -448 48
WIRE -272 64 -448 64
WIRE 256 64 256 16
WIRE -448 80 -448 64
WIRE 208 80 176 80
WIRE 208 128 192 128
WIRE -272 144 -272 64
WIRE 176 144 176 80
WIRE 176 144 -272 144
WIRE 192 160 192 128
WIRE 256 160 256 144
WIRE 256 160 192 160
WIRE 256 176 256 160
WIRE -448 192 -448 160
WIRE -416 240 -480 240
WIRE -320 240 -336 240
WIRE -480 272 -480 240
WIRE -320 272 -320 240
WIRE -208 272 -320 272
WIRE -320 288 -320 272
WIRE -112 288 -112 -16
WIRE -208 368 -208 272
WIRE -208 368 -272 368
WIRE -160 368 -208 368
WIRE -480 400 -480 352
WIRE -320 400 -320 384
WIRE -320 400 -480 400
WIRE -208 400 -320 400
WIRE -112 400 -112 384
WIRE -112 400 -208 400
WIRE -208 432 -208 400
FLAG 224 -160 Vout
FLAG -112 -16 VS
FLAG 336 -416 0
FLAG 256 176 0
FLAG -448 192 0
FLAG -448 -64 Vin1
FLAG 240 -64 Vin2
FLAG -112 -80 0
FLAG -208 432 0
FLAG -208 368 VG_mirror
FLAG 480 -112 0
SYMBOL voltage -448 -48 R0
SYMATTR InstName VCOM_1
SYMATTR Value 1V
SYMBOL voltage 208 -432 R270
SYMATTR InstName VDD
SYMATTR Value 1.8
SYMBOL e 256 48 R0
SYMATTR InstName VDIFF_2
SYMATTR Value -1
SYMBOL voltage 256 -80 R0
SYMATTR Value 1V
SYMATTR InstName VCOM_2
SYMBOL voltage -448 64 R0
SYMATTR Value2 AC 200u
SYMATTR InstName VDIFF_1
SYMATTR Value PULSE(0 200u 1m 10m 0 10s)
SYMBOL nmos4 -384 -144 R0
SYMATTR InstName M1
SYMATTR Value nmos_custom
SYMBOL nmos4 160 -144 M0
SYMATTR Value nmos_custom
SYMATTR InstName M2
SYMBOL pmos4 64 -384 R0
SYMATTR InstName M3
SYMATTR Value pmos_custom
SYMBOL pmos4 -288 -384 M0
SYMATTR InstName M4
SYMATTR Value pmos_custom
SYMBOL nmos -160 288 R0
SYMATTR InstName M5
SYMATTR Value SQJ910AEP_Q2
SYMBOL nmos -272 288 M0
SYMATTR InstName M6
SYMATTR Value SQJ910AEP_Q2
SYMBOL res -320 224 R90
SYMATTR InstName R1
SYMATTR Value 1k
SYMBOL voltage -480 256 R0
SYMATTR Value 2.10179
SYMATTR InstName V1
SYMBOL cap 416 -176 R90
SYMATTR InstName C1
SYMATTR Value 1p