* SPICE netlist
D1 Cext1 VCC Dio
D2 Cext2 VCC Dio
S1c N003 Cext1 PSW 0 SW
S2c N003 Cext2 NSW 0 SW
M1 N003 VCOin R1 R1 BSS123
M2 N003 Th_ref R2 R2 BSS123
S1v Cext1 VCC NSW 0 SW
S2v Cext2 VCC PSW 0 SW
AsrFf N001 N002 0 0 0 NSW PSW 0 SRFLOP Td=10ns Trise=10ns Tfall=10ns
C1 Cext1 Cext2 10n
A1 Th_ref Cext2 0 0 0 0 N001 0 SCHMITT Vt=0 Vh=.1
A2 Th_ref Cext1 0 0 0 0 N002 0 SCHMITT Vt=0 Vh=.1
V+ VCC 0 {Vdd}
Vctl VCOin 0 PULSE(0 {Vdd} 0 2m 2m 1m)
R1 R1 0 10k
R2 R2 0 100k
Vref Th_ref 0 {Vdd*.6}
Eout VCOout 0 PSW 0 {Vdd}
bdem Demout 0 V=v(vcoin)*(1-u(v(inh)))
Rdem Demout 0 1g
Rinh Inh 0 1e6
Dz 0 Zener Zen
Rz Zener 0 1g
.tran 5ms
.param Vdd=10
+Isr=1.8n Nr=2 Bv=7 Ibv=27.721m Nbv=1.178 Ibvl=1.165m Nbvl=21.894 Tbv1=176.47u)

* LTspice schematic (.asc)
Version 4
SHEET 1 1728 432
WIRE 528 -216 512 -216
WIRE 704 -216 640 -216
WIRE 864 -216 848 -216
WIRE 512 -200 512 -216
WIRE 576 -200 512 -200
WIRE 640 -200 640 -216
WIRE 848 -200 752 -200
WIRE 864 -200 864 -216
WIRE 864 -200 848 -200
WIRE 512 -184 512 -200
WIRE 576 -184 576 -200
WIRE 704 -184 704 -216
WIRE 752 -184 752 -200
WIRE 848 -184 848 -200
WIRE 112 -136 16 -136
WIRE 240 -136 112 -136
WIRE 336 -136 240 -136
WIRE 352 -136 336 -136
WIRE 16 -104 16 -136
WIRE 336 -104 336 -136
WIRE -32 -88 -48 -88
WIRE 112 -88 112 -136
WIRE 240 -88 240 -136
WIRE 400 -88 384 -88
WIRE 512 -88 512 -120
WIRE 576 -88 576 -104
WIRE 576 -88 512 -88
WIRE 640 -88 640 -120
WIRE 640 -88 576 -88
WIRE 752 -88 752 -104
WIRE 752 -88 640 -88
WIRE 848 -88 848 -104
WIRE 848 -88 752 -88
WIRE -352 -72 -384 -72
WIRE 848 -72 848 -88
WIRE -512 -24 -528 -24
WIRE -32 -24 -32 -40
WIRE 384 -24 384 -40
WIRE -384 -8 -384 -72
WIRE -352 -8 -384 -8
WIRE -256 8 -288 8
WIRE 16 8 16 -24
WIRE 112 8 112 -24
WIRE 112 8 16 8
WIRE 240 8 240 -24
WIRE 336 8 336 -24
WIRE 336 8 240 8
WIRE -416 24 -416 8
WIRE -352 24 -416 24
WIRE -864 40 -864 -24
WIRE -720 40 -720 -8
WIRE 16 40 16 8
WIRE 336 40 336 8
WIRE -352 56 -352 40
WIRE -256 56 -256 8
WIRE -224 56 -256 56
WIRE -96 56 -128 56
WIRE -624 72 -624 40
WIRE -512 72 -512 40
WIRE 496 88 496 40
WIRE 608 88 608 40
WIRE 864 88 864 56
WIRE -224 104 -256 104
WIRE -96 104 -112 104
WIRE 112 104 112 8
WIRE 240 104 240 8
WIRE 432 104 432 88
WIRE 448 104 432 104
WIRE 544 104 544 88
WIRE 560 104 544 104
WIRE 688 104 688 72
WIRE 64 120 64 104
WIRE 288 120 288 104
WIRE -384 136 -384 -8
WIRE -352 136 -384 136
WIRE -256 152 -256 104
WIRE -256 152 -288 152
WIRE -224 152 -224 136
WIRE -416 168 -416 152
WIRE -352 168 -416 168
WIRE -864 184 -864 120
WIRE -720 184 -720 120
WIRE -624 184 -624 152
WIRE -512 184 -512 152
WIRE 64 184 64 168
WIRE 288 184 288 168
WIRE 688 184 688 152
WIRE 736 184 736 168
WIRE 736 184 688 184
WIRE -352 200 -352 184
WIRE 736 200 736 184
WIRE 864 200 864 168
WIRE 112 216 112 184
WIRE 240 216 240 184
WIRE 240 216 112 216
WIRE 496 216 496 184
WIRE 496 216 240 216
WIRE 608 216 608 184
WIRE 608 216 496 216
FLAG 16 40 Cext1
IOPIN -400 656 BiDir
FLAG 336 40 Cext2
IOPIN -80 656 BiDir
FLAG 352 -136 VCC
IOPIN -64 480 In
FLAG 288 184 0
FLAG 496 40 R1
IOPIN 80 656 BiDir
FLAG 608 40 R2
IOPIN 192 656 BiDir
FLAG -96 56 PSW
IOPIN -512 672 Out
FLAG -96 104 NSW
IOPIN -512 720 Out
FLAG 64 184 0
FLAG 64 104 PSW
IOPIN -352 720 In
FLAG 288 104 NSW
IOPIN -128 720 In
FLAG -32 -24 0
FLAG 384 -24 0
FLAG 400 -88 PSW
IOPIN -16 528 In
FLAG -48 -88 NSW
IOPIN -464 528 In
FLAG -592 -24 Cext1
FLAG -512 -24 Cext2
FLAG -224 152 0
FLAG -416 8 Cext2
IOPIN -832 624 In
FLAG -416 152 Cext1
IOPIN -832 768 In
FLAG 864 200 0
FLAG 864 56 Th_ref
IOPIN 448 672 Out
FLAG -352 -72 Th_ref
IOPIN -768 544 In
FLAG -864 184 0
FLAG -864 -24 VCC
IOPIN -1280 592 Out
FLAG -720 184 0
FLAG -720 -8 VCOin
IOPIN -1136 608 Out
FLAG 544 88 Th_ref
IOPIN 128 704 In
FLAG 432 88 VCOin
IOPIN 16 704 In
FLAG -352 56 0
FLAG -352 200 0
FLAG -624 184 0
FLAG -624 40 R1
FLAG -512 184 0
FLAG -512 40 R2
FLAG 736 88 VCOout
IOPIN 320 704 Out
FLAG 736 200 0
FLAG 688 72 PSW
IOPIN 272 688 In
FLAG 848 -216 Demout
IOPIN 432 400 Out
FLAG 848 -72 0
FLAG 704 -184 Inh
IOPIN 288 432 In
FLAG 528 -216 Zener
IOPIN 112 400 Out
SYMBOL diode 96 -24 M180
SYMATTR InstName D1
SYMATTR Value Dio
SYMBOL diode 256 -24 R180
SYMATTR InstName D2
SYMATTR Value Dio
SYMBOL sw 112 200 M180
SYMATTR InstName S1c
SYMBOL sw 240 200 R180
SYMATTR InstName S2c
SYMBOL nmos 448 184 M180
SYMATTR InstName M1
SYMATTR Value BSS123
SYMBOL nmos 560 184 M180
SYMATTR InstName M2
SYMATTR Value BSS123
SYMBOL sw 16 -8 M180
SYMATTR InstName S1v
SYMBOL sw 336 -8 R180
SYMATTR InstName S2v
SYMBOL Digital\\srflop -176 8 R0
SYMATTR Value Td=10ns Trise=10ns Tfall=10ns
SYMATTR InstName AsrFf
SYMBOL cap -592 -8 R270
SYMATTR InstName C1
SYMATTR Value 10n
SYMBOL Digital\\diffschmtbuf -352 -56 R0
SYMATTR Value Vt=0 Vh=.1
SYMATTR InstName A1
SYMBOL Digital\\diffschmtbuf -352 88 R0
SYMATTR Value Vt=0 Vh=.1
SYMATTR InstName A2
SYMBOL voltage -864 24 R0
SYMATTR Value {Vdd}
SYMATTR InstName V+
SYMBOL voltage -720 24 R0
SYMATTR Value PULSE(0 {Vdd} 0 2m 2m 1m)
SYMATTR InstName Vctl
SYMBOL Misc\\EuropeanResistor -640 56 R0
SYMATTR InstName R1
SYMATTR Value 10k
SYMBOL Misc\\EuropeanResistor -528 56 R0
SYMATTR InstName R2
SYMATTR Value 100k
SYMBOL voltage 864 72 R0
SYMATTR InstName Vref
SYMATTR Value {Vdd*.6}
SYMBOL e 736 72 R0
SYMATTR InstName Eout
SYMATTR Value {Vdd}
SYMBOL bv 848 -200 R0
SYMATTR InstName bdem
SYMATTR Value V=v(vcoin)*(1-u(v(inh)))
SYMBOL res 736 -200 R0
SYMATTR InstName Rdem
SYMATTR Value 1g
SYMBOL res 624 -216 R0
SYMATTR InstName Rinh
SYMATTR Value 1e6
SYMBOL zener 528 -120 R180
SYMATTR InstName Dz
SYMATTR Value Zen
SYMBOL res 560 -200 R0
SYMATTR InstName Rz
SYMATTR Value 1g