* SPICE netlist
M1 N020 vgb 0 0 NMOS_VTL l=50n w=150n
M2 N019 N017 N020 0 NMOS_VTL l=50n w=150n
M3 N018 vgb N019 0 NMOS_VTL l=50n w=150n
M4 vd_m4 N017 N018 0 NMOS_VTL l=50n w=150n
C50f 0 vd_m4 {CL}
C2 N019 0 {CL}
C3 N018 vg {Cdec}
C4 N017 vg {Cdec}
C5 N020 vg {Cdec}
R1 N017 vgb {Rval}
V1 vgb 0 {Vgb}
R2 vg 0 50
S1 vg N022 N021 P001 MYSW
I1 0 N022 SINE(0 20uA 900Meg)
R3 N022 0 1Meg
V2 N021 P001 PULSE(0 -1 0 1f 1f 10u 20u)
M5 N013 vgb vd_m4 0 NMOS_VTL l=50n w=150n
M6 N009 N001 N013 0 NMOS_VTL l=50n w=150n
M7 N005 vgb N009 0 NMOS_VTL l=50n w=150n
M8 vd_m8 N001 N005 0 NMOS_VTL l=50n w=150n
C6 0 vd_m8 {CL}
C7 N009 0 {CL}
C8 N005 vg {Cdec}
C9 N001 vg {Cdec}
C10 N013 vg {Cdec}
R4 N001 vgb {Rval}
M9 N014 vgb vd_m8 0 NMOS_VTL l=50n w=150n
M10 N010 N002 N014 0 NMOS_VTL l=50n w=150n
M11 N006 vgb N010 0 NMOS_VTL l=50n w=150n
M12 vd_m12 N002 N006 0 NMOS_VTL l=50n w=150n
C11 0 vd_m12 {CL}
C12 N010 0 {CL}
C13 N006 vg {Cdec}
C14 N002 vg {Cdec}
C15 N014 vg {Cdec}
R5 N002 vgb {Rval}
M13 N015 vgb vd_m12 0 NMOS_VTL l=50n w=150n
M14 N011 N003 N015 0 NMOS_VTL l=50n w=150n
M15 N007 vgb N011 0 NMOS_VTL l=50n w=150n
M16 vd_m16 N003 N007 0 NMOS_VTL l=50n w=150n
C16 0 vd_m16 {CL}
C17 N011 0 {CL}
C18 N007 vg {Cdec}
C19 N003 vg {Cdec}
C20 N015 vg {Cdec}
R6 N003 vgb {Rval}
M17 N016 vgb vd_m16 0 NMOS_VTL l=50n w=150n
M18 N012 N004 N016 0 NMOS_VTL l=50n w=150n
M19 N008 vgb N012 0 NMOS_VTL l=50n w=150n
M20 vd_m20 N004 N008 0 NMOS_VTL l=50n w=150n
C21 0 vd_m20 {CL}
C22 N012 0 {CL}
C23 N008 vg {Cdec}
C24 N004 vg {Cdec}
C25 N016 vg {Cdec}
R7 N004 vgb {Rval}
.tran 0.05m
.param CL=25f
.param Cdec=25f
.param Rval=680k
.param Vgb=0.14

* LTspice schematic (.asc)
Version 4
SHEET 1 3360 2128
WIRE -1088 -1048 -1152 -1048
WIRE -960 -1048 -1024 -1048
WIRE -208 -1048 -272 -1048
WIRE -80 -1048 -144 -1048
WIRE 672 -1048 608 -1048
WIRE 800 -1048 736 -1048
WIRE 1552 -1048 1488 -1048
WIRE 1680 -1048 1616 -1048
WIRE -960 -1032 -960 -1048
WIRE -80 -1032 -80 -1048
WIRE 800 -1032 800 -1048
WIRE 1680 -1032 1680 -1048
WIRE -1152 -968 -1152 -1048
WIRE -272 -968 -272 -1048
WIRE 608 -968 608 -1048
WIRE 1488 -968 1488 -1048
WIRE -1200 -888 -1280 -888
WIRE -320 -888 -400 -888
WIRE 560 -888 480 -888
WIRE 1440 -888 1360 -888
WIRE -1440 -808 -1616 -808
WIRE -1152 -808 -1152 -872
WIRE -1152 -808 -1376 -808
WIRE -560 -808 -736 -808
WIRE -272 -808 -272 -872
WIRE -272 -808 -496 -808
WIRE 320 -808 144 -808
WIRE 608 -808 608 -872
WIRE 608 -808 384 -808
WIRE 1200 -808 1024 -808
WIRE 1488 -808 1488 -872
WIRE 1488 -808 1264 -808
WIRE -1152 -760 -1152 -808
WIRE -272 -760 -272 -808
WIRE 608 -760 608 -808
WIRE 1488 -760 1488 -808
WIRE -1200 -680 -1216 -680
WIRE -320 -680 -336 -680
WIRE 560 -680 544 -680
WIRE 1440 -680 1424 -680
WIRE -1616 -632 -1616 -808
WIRE -1440 -632 -1616 -632
WIRE -1280 -632 -1280 -888
WIRE -1280 -632 -1376 -632
WIRE -736 -632 -736 -808
WIRE -560 -632 -736 -632
WIRE -400 -632 -400 -888
WIRE -400 -632 -496 -632
WIRE 144 -632 144 -808
WIRE 320 -632 144 -632
WIRE 480 -632 480 -888
WIRE 480 -632 384 -632
WIRE 1024 -632 1024 -808
WIRE 1200 -632 1024 -632
WIRE 1360 -632 1360 -888
WIRE 1360 -632 1264 -632
WIRE -1152 -616 -1152 -664
WIRE -1008 -616 -1152 -616
WIRE -272 -616 -272 -664
WIRE -128 -616 -272 -616
WIRE 608 -616 608 -664
WIRE 752 -616 608 -616
WIRE 1488 -616 1488 -664
WIRE 1632 -616 1488 -616
WIRE -1008 -600 -1008 -616
WIRE -128 -600 -128 -616
WIRE 752 -600 752 -616
WIRE 1632 -600 1632 -616
WIRE -1008 -584 -1008 -600
WIRE -128 -584 -128 -600
WIRE 752 -584 752 -600
WIRE 1632 -584 1632 -600
WIRE -1152 -568 -1152 -616
WIRE -272 -568 -272 -616
WIRE 608 -568 608 -616
WIRE 1488 -568 1488 -616
WIRE -1520 -520 -1680 -520
WIRE -1456 -520 -1520 -520
WIRE -1280 -520 -1280 -632
WIRE -1280 -520 -1376 -520
WIRE -640 -520 -800 -520
WIRE -576 -520 -640 -520
WIRE -400 -520 -400 -632
WIRE -400 -520 -496 -520
WIRE 240 -520 80 -520
WIRE 304 -520 240 -520
WIRE 480 -520 480 -632
WIRE 480 -520 384 -520
WIRE 1120 -520 960 -520
WIRE 1184 -520 1120 -520
WIRE 1360 -520 1360 -632
WIRE 1360 -520 1264 -520
WIRE -1280 -488 -1280 -520
WIRE -1200 -488 -1280 -488
WIRE -400 -488 -400 -520
WIRE -320 -488 -400 -488
WIRE 480 -488 480 -520
WIRE 560 -488 480 -488
WIRE 1360 -488 1360 -520
WIRE 1440 -488 1360 -488
WIRE -1616 -424 -1616 -632
WIRE -1440 -424 -1616 -424
WIRE -1152 -424 -1152 -472
WIRE -1152 -424 -1376 -424
WIRE -736 -424 -736 -632
WIRE -560 -424 -736 -424
WIRE -272 -424 -272 -472
WIRE -272 -424 -496 -424
WIRE 144 -424 144 -632
WIRE 320 -424 144 -424
WIRE 608 -424 608 -472
WIRE 608 -424 384 -424
WIRE 1024 -424 1024 -632
WIRE 1200 -424 1024 -424
WIRE 1488 -424 1488 -472
WIRE 1488 -424 1264 -424
WIRE -1152 -376 -1152 -424
WIRE -272 -376 -272 -424
WIRE 608 -376 608 -424
WIRE 1488 -376 1488 -424
WIRE -1520 -296 -1520 -520
WIRE -1216 -296 -1216 -680
WIRE -1216 -296 -1520 -296
WIRE -1200 -296 -1216 -296
WIRE -640 -296 -640 -520
WIRE -336 -296 -336 -680
WIRE -336 -296 -640 -296
WIRE -320 -296 -336 -296
WIRE 240 -296 240 -520
WIRE 544 -296 544 -680
WIRE 544 -296 240 -296
WIRE 560 -296 544 -296
WIRE 1120 -296 1120 -520
WIRE 1424 -296 1424 -680
WIRE 1424 -296 1120 -296
WIRE 1440 -296 1424 -296
WIRE -1616 -232 -1616 -424
WIRE -736 -232 -736 -424
WIRE 144 -232 144 -424
WIRE 1024 -232 1024 -424
WIRE -1152 -200 -1152 -280
WIRE -272 -200 -272 -280
WIRE 608 -200 608 -280
WIRE 1488 -200 1488 -280
WIRE 1008 104 944 104
WIRE 1136 104 1072 104
WIRE 1136 120 1136 104
WIRE 944 184 944 104
WIRE 896 264 816 264
WIRE 656 344 480 344
WIRE 944 344 944 280
WIRE 944 344 720 344
WIRE 944 392 944 344
WIRE 896 472 880 472
WIRE 480 520 480 344
WIRE 656 520 480 520
WIRE 816 520 816 264
WIRE 816 520 720 520
WIRE 944 536 944 488
WIRE 1088 536 944 536
WIRE 1088 552 1088 536
WIRE 1088 568 1088 552
WIRE 944 584 944 536
WIRE 576 632 400 632
WIRE 640 632 576 632
WIRE 816 632 816 520
WIRE 816 632 720 632
WIRE 400 648 400 632
WIRE 816 664 816 632
WIRE 896 664 816 664
WIRE 480 728 480 520
WIRE 656 728 480 728
WIRE 944 728 944 680
WIRE 944 728 720 728
WIRE 400 744 400 728
WIRE 320 776 272 776
WIRE 944 776 944 728
WIRE 320 792 320 776
WIRE 576 856 576 632
WIRE 880 856 880 472
WIRE 880 856 576 856
WIRE 896 856 880 856
WIRE 272 872 272 776
WIRE 192 920 -80 920
WIRE 256 920 192 920
WIRE 416 920 336 920
WIRE 480 920 480 728
WIRE 480 920 416 920
WIRE -80 952 -80 920
WIRE 192 952 192 920
WIRE 416 952 416 920
WIRE 944 952 944 872
WIRE -80 1064 -80 1032
WIRE 192 1064 192 1032
WIRE 416 1064 416 1032
FLAG 944 952 0
FLAG 944 232 0
FLAG 944 440 0
FLAG 944 632 0
FLAG 944 824 0
FLAG 1136 120 0
FLAG 1088 616 0
FLAG 400 744 0
FLAG 416 1064 0
FLAG 192 1064 0
FLAG -80 1064 0
FLAG -1152 -920 0
FLAG -1152 -712 0
FLAG -1152 -520 0
FLAG -1152 -328 0
FLAG -960 -1032 0
FLAG -1008 -536 0
FLAG -1152 -1048 vd_m8
FLAG -1616 -232 vg
FLAG -1152 -200 vd_m4
FLAG 480 920 vg
FLAG 400 632 vgb
FLAG -1680 -520 vgb
FLAG -272 -920 0
FLAG -272 -712 0
FLAG -272 -520 0
FLAG -272 -328 0
FLAG -80 -1032 0
FLAG -128 -536 0
FLAG -272 -1048 vd_m12
FLAG -736 -232 vg
FLAG -272 -200 vd_m8
FLAG -800 -520 vgb
FLAG 608 -920 0
FLAG 608 -712 0
FLAG 608 -520 0
FLAG 608 -328 0
FLAG 800 -1032 0
FLAG 752 -536 0
FLAG 608 -1048 vd_m16
FLAG 144 -232 vg
FLAG 608 -200 vd_m12
FLAG 80 -520 vgb
FLAG 1488 -920 0
FLAG 1488 -712 0
FLAG 1488 -520 0
FLAG 1488 -328 0
FLAG 1680 -1032 0
FLAG 1632 -536 0
FLAG 1488 -1048 vd_m20
FLAG 1024 -232 vg
FLAG 1488 -200 vd_m16
FLAG 960 -520 vgb
FLAG 944 104 vd_m4
SYMBOL nmos4 896 776 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M1
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 896 584 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M2
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 896 392 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M3
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 896 184 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M4
SYMATTR Value2 l=50n w=150n
SYMBOL cap 1072 88 R90
SYMATTR InstName 50f
SYMATTR Value {CL}
SYMBOL cap 1072 552 R0
SYMATTR Value {CL}
SYMATTR InstName C2
SYMBOL cap 720 328 R90
SYMATTR InstName C3
SYMATTR Value {Cdec}
SYMBOL cap 720 504 R90
SYMATTR InstName C4
SYMATTR Value {Cdec}
SYMBOL cap 720 712 R90
SYMATTR InstName C5
SYMATTR Value {Cdec}
SYMBOL res 736 616 R90
SYMATTR InstName R1
SYMATTR Value {Rval}
SYMBOL voltage 400 632 R0
SYMATTR Value {Vgb}
SYMATTR InstName V1
SYMBOL res 400 936 R0
SYMATTR InstName R2
SYMATTR Value 50
SYMBOL sw 352 920 R90
SYMATTR InstName S1
SYMATTR Value MYSW
SYMBOL current 192 1032 R180
SYMATTR InstName I1
SYMATTR Value SINE(0 20uA 900Meg)
SYMBOL res -96 936 R0
SYMATTR InstName R3
SYMATTR Value 1Meg
SYMBOL voltage 320 776 R0
SYMATTR Value PULSE(0 -1 0 1f 1f 10u 20u)
SYMATTR InstName V2
SYMBOL nmos4 -1200 -376 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M5
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 -1200 -568 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M6
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 -1200 -760 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M7
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 -1200 -968 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M8
SYMATTR Value2 l=50n w=150n
SYMBOL cap -1024 -1064 R90
SYMATTR InstName C6
SYMATTR Value {CL}
SYMBOL cap -1024 -600 R0
SYMATTR Value {CL}
SYMATTR InstName C7
SYMBOL cap -1376 -824 R90
SYMATTR InstName C8
SYMATTR Value {Cdec}
SYMBOL cap -1376 -648 R90
SYMATTR InstName C9
SYMATTR Value {Cdec}
SYMBOL cap -1376 -440 R90
SYMATTR InstName C10
SYMATTR Value {Cdec}
SYMBOL res -1360 -536 R90
SYMATTR InstName R4
SYMATTR Value {Rval}
SYMBOL nmos4 -320 -376 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M9
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 -320 -568 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M10
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 -320 -760 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M11
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 -320 -968 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M12
SYMATTR Value2 l=50n w=150n
SYMBOL cap -144 -1064 R90
SYMATTR InstName C11
SYMATTR Value {CL}
SYMBOL cap -144 -600 R0
SYMATTR Value {CL}
SYMATTR InstName C12
SYMBOL cap -496 -824 R90
SYMATTR InstName C13
SYMATTR Value {Cdec}
SYMBOL cap -496 -648 R90
SYMATTR InstName C14
SYMATTR Value {Cdec}
SYMBOL cap -496 -440 R90
SYMATTR InstName C15
SYMATTR Value {Cdec}
SYMBOL res -480 -536 R90
SYMATTR InstName R5
SYMATTR Value {Rval}
SYMBOL nmos4 560 -376 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M13
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 560 -568 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M14
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 560 -760 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M15
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 560 -968 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M16
SYMATTR Value2 l=50n w=150n
SYMBOL cap 736 -1064 R90
SYMATTR InstName C16
SYMATTR Value {CL}
SYMBOL cap 736 -600 R0
SYMATTR Value {CL}
SYMATTR InstName C17
SYMBOL cap 384 -824 R90
SYMATTR InstName C18
SYMATTR Value {Cdec}
SYMBOL cap 384 -648 R90
SYMATTR InstName C19
SYMATTR Value {Cdec}
SYMBOL cap 384 -440 R90
SYMATTR InstName C20
SYMATTR Value {Cdec}
SYMBOL res 400 -536 R90
SYMATTR InstName R6
SYMATTR Value {Rval}
SYMBOL nmos4 1440 -376 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M17
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 1440 -568 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M18
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 1440 -760 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M19
SYMATTR Value2 l=50n w=150n
SYMBOL nmos4 1440 -968 R0
SYMATTR Value NMOS_VTL
SYMATTR InstName M20
SYMATTR Value2 l=50n w=150n
SYMBOL cap 1616 -1064 R90
SYMATTR InstName C21
SYMATTR Value {CL}
SYMBOL cap 1616 -600 R0
SYMATTR Value {CL}
SYMATTR InstName C22
SYMBOL cap 1264 -824 R90
SYMATTR InstName C23
SYMATTR Value {Cdec}
SYMBOL cap 1264 -648 R90
SYMATTR InstName C24
SYMATTR Value {Cdec}
SYMBOL cap 1264 -440 R90
SYMATTR InstName C25
SYMATTR Value {Cdec}
SYMBOL res 1280 -536 R90
SYMATTR InstName R7
SYMATTR Value {Rval}