* SPICE netlist
V1 Vref 0 5
V2 9 0 PULSE(0 6 0 1500u 1u 1u 1700u)
R2 12 0 100k
XU1 12 Vref A opamp Aol=100K GBW=10Meg ;pnba invin)noninvin)out
V3 _inh 0 5
R1 11 0 80k
XU16 11 9 B opamp Aol=100K GBW=10Meg ;pnba invin)noninvin)out
R5 A N003 10
M3 11 11 B B QP
M4 N007 11 N006 N006 QP
D1 N004 N005 1N914
D2 N007 N005 1N914
R6 B N006 10
M1 12 12 A A QP
M2 N004 12 N003 N003 QP
R7 N005 N001 1
R8 A 12 100k
R9 11 B 100k
C2 C1B C1A 220p
B1 VCO_out 0 V=V(Gate2)*V(Vref)
B4 _VCO_out 0 V=V(Gate1)*V(Vref)
S1 0 C1A Gate2 0 SW
S2 C1B N001 Gate2 0 SW
S3 0 C1B Gate1 0 SW
S4 C1A N001 Gate1 0 SW
A1 C1B 0 0 0 0 0 N002 0 SCHMITT Vt=1.1 Vh=0
A2 C1A 0 0 0 0 0 N008 0 SCHMITT Vt=1.1 Vh=0
A3 N008 N002 0 0 0 Gate1 Gate2 0 SRFLOP Td=10ns Trise=10ns Tfall=10ns
D3 C1A N001 1N746
D4 0 C1A 1N746
D5 C1B N001 1N746
D6 0 C1B 1N746
.tran 2000u
.ic V(C1A)=0 V(C1B)=0
.inc "C:\Program Files\LTC\LTspiceIV\lib\sym\Extra\CD4000\CD4000.lib"

* LTspice schematic (.asc)
Version 4
SHEET 1 2288 1088
WIRE -504 -496 -504 -544
WIRE -376 -496 -376 -528
WIRE 40 -496 40 -544
WIRE -504 -384 -504 -416
WIRE -376 -384 -376 -416
WIRE 40 -384 40 -416
WIRE -888 -192 -936 -192
WIRE -776 -176 -824 -176
WIRE -744 -176 -776 -176
WIRE -888 -160 -920 -160
WIRE 24 -160 -8 -160
WIRE 328 -144 296 -144
WIRE -8 -128 -8 -160
WIRE 88 -128 40 -128
WIRE 296 -128 296 -144
WIRE 376 -128 344 -128
WIRE -664 -96 -664 -160
WIRE -552 -96 -664 -96
WIRE -440 -96 -456 -96
WIRE -408 -96 -440 -96
WIRE 1144 -96 1144 -160
WIRE -920 -80 -920 -160
WIRE -920 -80 -936 -80
WIRE -888 -80 -920 -80
WIRE -776 -80 -776 -176
WIRE -776 -80 -808 -80
WIRE -24 -80 -72 -80
WIRE 168 -80 56 -80
WIRE 280 -80 168 -80
WIRE 376 -80 376 -128
WIRE 376 -80 360 -80
WIRE 392 -80 376 -80
WIRE 600 -32 584 -32
WIRE -536 -16 -536 -48
WIRE -440 -16 -440 -96
WIRE -440 -16 -536 -16
WIRE 584 0 584 -32
WIRE -536 16 -536 -16
WIRE -72 16 -72 -80
WIRE 8 16 -72 16
WIRE 168 16 168 -80
WIRE 168 16 72 16
WIRE 248 16 168 16
WIRE 344 16 312 16
WIRE 1144 16 1144 -16
WIRE 584 32 536 32
WIRE 712 48 648 48
WIRE 760 48 744 48
WIRE -664 64 -664 -96
WIRE -648 64 -664 64
WIRE -552 64 -568 64
WIRE -392 64 -456 64
WIRE -216 64 -328 64
WIRE -1128 80 -1128 48
WIRE -984 80 -984 48
WIRE 744 80 744 48
WIRE 168 96 168 16
WIRE 168 96 152 96
WIRE -216 112 -216 64
WIRE -184 112 -216 112
WIRE -72 112 -72 16
WIRE -72 112 -104 112
WIRE 344 112 344 16
WIRE 376 112 344 112
WIRE 712 112 712 48
WIRE 744 112 712 112
WIRE 888 112 856 112
WIRE 168 144 152 144
WIRE -648 160 -664 160
WIRE -552 160 -568 160
WIRE -392 160 -456 160
WIRE -216 160 -216 112
WIRE -216 160 -328 160
WIRE 744 160 712 160
WIRE 888 160 840 160
WIRE 600 176 584 176
WIRE -1128 192 -1128 160
WIRE -984 192 -984 160
WIRE 584 192 584 176
WIRE -72 224 -72 112
WIRE 8 224 -72 224
WIRE 168 224 168 144
WIRE 168 224 72 224
WIRE 248 224 168 224
WIRE 344 224 344 112
WIRE 344 224 312 224
WIRE 584 224 536 224
WIRE -536 240 -536 208
WIRE -440 240 -536 240
WIRE 712 240 712 160
WIRE 712 240 648 240
WIRE -536 272 -536 240
WIRE 1144 272 1144 208
WIRE -1096 288 -1128 288
WIRE -984 288 -1032 288
WIRE -72 304 -72 224
WIRE -24 304 -72 304
WIRE 168 304 168 224
WIRE 168 304 56 304
WIRE 280 304 168 304
WIRE 376 304 360 304
WIRE 392 304 376 304
WIRE -664 320 -664 160
WIRE -552 320 -664 320
WIRE -440 320 -440 240
WIRE -440 320 -456 320
WIRE -408 320 -440 320
WIRE 72 352 40 352
WIRE 376 352 376 304
WIRE 376 352 344 352
WIRE 296 368 296 352
WIRE 328 368 296 368
WIRE -8 384 -8 352
WIRE 40 384 -8 384
WIRE 1144 384 1144 352
WIRE -664 416 -664 320
WIRE -872 432 -920 432
WIRE -760 448 -808 448
WIRE -728 448 -760 448
WIRE -872 464 -904 464
WIRE -904 544 -904 464
WIRE -904 544 -936 544
WIRE -888 544 -904 544
WIRE -760 544 -760 448
WIRE -760 544 -808 544
FLAG -376 -384 0
FLAG -504 -384 0
FLAG -504 -544 Vref
FLAG -936 -192 Vref
FLAG -984 192 0
FLAG 392 -80 0
FLAG 392 304 0
FLAG 24 -160 Gate1
FLAG 40 384 Gate2
FLAG 152 96 C1A
IOPIN 1264 112 BiDir
FLAG 152 144 C1B
IOPIN 1264 160 BiDir
FLAG 888 112 Gate1
FLAG 40 -384 0
FLAG 40 -544 _inh
FLAG -1128 192 0
FLAG 376 112 0
FLAG -744 -176 A
FLAG -728 448 B
FLAG -664 416 B
FLAG -664 -160 A
FLAG -1128 48 11
IOPIN -16 64 BiDir
FLAG -984 48 12
IOPIN 128 64 BiDir
FLAG -936 -80 12
IOPIN 176 -64 BiDir
FLAG -936 544 11
IOPIN 176 560 BiDir
FLAG -920 432 9
IOPIN 192 448 BiDir
FLAG -376 -528 9
IOPIN 736 -512 BiDir
FLAG -1128 288 C1A
IOPIN -16 304 BiDir
FLAG -984 288 C1B
IOPIN 128 304 BiDir
FLAG -408 -96 12
IOPIN 704 -80 BiDir
FLAG -408 320 11
IOPIN 704 336 BiDir
FLAG 1144 16 0
FLAG 1144 384 0
FLAG 888 160 Gate2
FLAG 88 -128 0
FLAG 72 352 0
FLAG 328 -144 Gate2
FLAG 328 368 Gate1
FLAG 600 -32 0
FLAG 600 176 0
FLAG 536 224 C1A
IOPIN 1648 240 BiDir
FLAG 536 32 C1B
IOPIN 1648 48 BiDir
FLAG 760 48 0
FLAG 1144 -160 VCO_out
FLAG 1144 208 _VCO_out
SYMBOL voltage -504 -512 R0
SYMATTR InstName V1
SYMATTR Value 5
SYMBOL voltage -376 -512 R0
SYMATTR InstName V2
SYMATTR Value PULSE(0 6 0 1500u 1u 1u 1700u)
SYMBOL res -1000 64 R0
SYMATTR InstName R2
SYMATTR Value 100k
SYMBOL Opamps\\opamp -856 -112 M180
SYMATTR InstName U1
SYMBOL voltage 40 -512 R0
SYMATTR InstName V3
SYMATTR Value 5
SYMBOL res -1144 64 R0
SYMATTR InstName R1
SYMATTR Value 80k
SYMBOL Opamps\\opamp -840 512 M180
SYMATTR InstName U16
SYMBOL res -664 80 R270
SYMATTR InstName R5
SYMATTR Value 10
SYMBOL pmos -456 272 R90
SYMATTR InstName M3
SYMATTR Value QP
SYMBOL pmos -456 208 M270
SYMATTR InstName M4
SYMATTR Value QP
SYMBOL diode -392 48 M90
SYMATTR Value 1N914
SYMATTR InstName D1
SYMBOL diode -392 176 R270
SYMATTR Value 1N914
SYMATTR InstName D2
SYMBOL res -664 144 M90
SYMATTR InstName R6
SYMATTR Value 10
SYMBOL pmos -456 -48 M270
SYMATTR InstName M1
SYMATTR Value QP
SYMBOL pmos -456 16 R90
SYMATTR InstName M2
SYMATTR Value QP
SYMBOL res -200 96 M90
SYMATTR InstName R7
SYMATTR Value 1
SYMBOL res -792 -96 R90
SYMATTR InstName R8
SYMATTR Value 100k
SYMBOL res -904 528 M90
SYMATTR InstName R9
SYMATTR Value 100k
SYMBOL cap -1032 272 R90
SYMATTR InstName C2
SYMATTR Value 220p
SYMBOL bv 1144 -112 R0
SYMATTR Value V=V(Gate2)*V(Vref)
SYMATTR InstName B1
SYMBOL bv 1144 256 R0
SYMATTR Value V=V(Gate1)*V(Vref)
SYMATTR InstName B4
SYMBOL sw 376 -80 R90
SYMATTR InstName S1
SYMBOL sw 72 304 M270
SYMATTR InstName S2
SYMBOL sw 376 304 M270
SYMATTR InstName S3
SYMBOL sw 72 -80 R90
SYMATTR InstName S4
SYMBOL Digital\\schmitt 584 96 M180
SYMATTR Value Vt=1.1 Vh=0
SYMATTR InstName A1
SYMBOL Digital\\schmitt 584 288 M180
SYMATTR Value Vt=1.1 Vh=0
SYMATTR InstName A2
SYMBOL Digital\\srflop 792 208 M180
SYMATTR Value Td=10ns Trise=10ns Tfall=10ns
SYMATTR InstName A3
SYMBOL zener 72 0 R90
SYMATTR InstName D3
SYMATTR Value 1N746
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL zener 312 0 R90
SYMATTR InstName D4
SYMATTR Value 1N746
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL zener 72 208 R90
SYMATTR InstName D5
SYMATTR Value 1N746
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL zener 312 208 R90
SYMATTR InstName D6
SYMATTR Value 1N746
SYMATTR Description Diode
SYMATTR Type diode