* SPICE netlist
M1 Vout Vg 0 0 nch_tt W=450n L=180n
R1 N004 Vout 25k
Vdd1 N004 0 1.2
C1 Vout 0 1p
M2 N006 Vg 0 0 nch_tt W=450n L=180n
M3 N001 N001 N006 N006 nch_tt W=450n L=180n
Vdd2 N001 0 1.2
C2 N006 0 1p
M4 N007 Vg 0 0 nch_tt W=450n L=180n
M5 N002 N003 N007 N007 nch_tt W=450n L=180n
Vdd3 N002 0 1.2
C3 N007 0 1p
Vdd4 N003 0 1.6
M6 N008 Vg 0 0 nch_tt W=450n L=180n
M7 N008 Vg N005 N005 PMOS
Vdd5 N005 0 1.2
C4 N008 0 1p
Vg Vg 0 V
.include "TSMC180.lib"
.dc Vg 0 1.2 1m

* LTspice schematic (.asc)
Version 4
SHEET 1 3248 560
WIRE -232 -264 -472 -264
WIRE 504 -248 264 -248
WIRE -472 -232 -472 -264
WIRE -472 -232 -568 -232
WIRE 168 -232 40 -232
WIRE -888 -216 -1064 -216
WIRE 40 -216 40 -232
WIRE -472 -200 -472 -232
WIRE -1064 -184 -1064 -216
WIRE -888 -184 -888 -216
WIRE 264 -184 264 -248
WIRE 1624 -168 1256 -168
WIRE 1624 -152 1624 -168
WIRE -568 -120 -568 -232
WIRE -520 -120 -568 -120
WIRE 168 -104 168 -232
WIRE 216 -104 168 -104
WIRE 1256 -104 1256 -168
WIRE 1208 -88 1144 -88
WIRE -1064 -56 -1064 -104
WIRE -968 -56 -1064 -56
WIRE -952 -56 -968 -56
WIRE -1064 -40 -1064 -56
WIRE -472 -40 -472 -104
WIRE -376 -40 -472 -40
WIRE -968 -24 -968 -56
WIRE 264 -24 264 -88
WIRE 360 -24 264 -24
WIRE 1384 -8 1256 -8
WIRE -472 8 -472 -40
WIRE -472 24 -472 8
WIRE 264 24 264 -24
WIRE 1384 24 1384 -8
WIRE -1112 40 -1224 40
WIRE 264 40 264 24
WIRE 1144 40 1144 -88
WIRE 1144 40 1016 40
WIRE -1224 72 -1224 40
WIRE 1016 72 1016 40
WIRE -520 88 -648 88
WIRE 1016 88 1016 72
WIRE 1256 88 1256 -8
WIRE 216 104 88 104
WIRE 1384 104 1384 88
WIRE -648 136 -648 88
WIRE 88 136 88 104
WIRE 88 152 88 136
WIRE 1144 168 1144 40
WIRE 1208 168 1144 168
WIRE -1064 216 -1064 56
WIRE 1256 216 1256 184
WIRE -472 264 -472 104
WIRE 264 280 264 120
FLAG -1064 216 0
FLAG -888 -104 0
FLAG -952 -56 Vout
IOPIN 224 96 Out
FLAG -968 40 0
FLAG -232 -184 0
FLAG -472 264 0
FLAG -376 24 0
FLAG 504 -168 0
FLAG 264 280 0
FLAG 360 40 0
FLAG 40 -136 0
FLAG 1624 -72 0
FLAG 1256 216 0
FLAG 1384 104 0
FLAG -1624 88 0
FLAG -1624 8 Vg
FLAG -1224 72 Vg
FLAG -648 136 Vg
FLAG 88 136 Vg
FLAG 1016 72 Vg
SYMBOL nmos -1112 -40 R0
SYMATTR InstName M1
SYMATTR Value nch_tt
SYMATTR Value2 W=450n L=180n
SYMBOL res -1080 -200 R0
SYMATTR InstName R1
SYMATTR Value 25k
SYMBOL voltage -888 -200 R0
SYMATTR InstName Vdd1
SYMATTR Value 1.2
SYMBOL cap -984 -24 R0
SYMATTR InstName C1
SYMATTR Value 1p
SYMBOL nmos -520 8 R0
SYMATTR InstName M2
SYMATTR Value nch_tt
SYMATTR Value2 W=450n L=180n
SYMBOL nmos -520 -200 R0
SYMATTR InstName M3
SYMATTR Value nch_tt
SYMATTR Value2 W=450n L=180n
SYMBOL voltage -232 -280 R0
SYMATTR InstName Vdd2
SYMATTR Value 1.2
SYMBOL cap -392 -40 R0
SYMATTR InstName C2
SYMATTR Value 1p
SYMBOL nmos 216 24 R0
SYMATTR InstName M4
SYMATTR Value nch_tt
SYMATTR Value2 W=450n L=180n
SYMBOL nmos 216 -184 R0
SYMATTR InstName M5
SYMATTR Value nch_tt
SYMATTR Value2 W=450n L=180n
SYMBOL voltage 504 -264 R0
SYMATTR InstName Vdd3
SYMATTR Value 1.2
SYMBOL cap 344 -24 R0
SYMATTR InstName C3
SYMATTR Value 1p
SYMBOL voltage 40 -232 R0
SYMATTR InstName Vdd4
SYMATTR Value 1.6
SYMBOL nmos 1208 88 R0
SYMATTR InstName M6
SYMATTR Value nch_tt
SYMATTR Value2 W=450n L=180n
SYMBOL pmos 1208 -8 M180
SYMATTR InstName M7
SYMBOL voltage 1624 -168 R0
SYMATTR InstName Vdd5
SYMATTR Value 1.2
SYMBOL cap 1368 24 R0
SYMATTR InstName C4
SYMATTR Value 1p
SYMBOL voltage -1624 -8 R0
SYMATTR InstName Vg