Version 4
SHEET 1 1156 680
WIRE 304 96 -80 96
WIRE -80 128 -80 96
WIRE 192 128 16 128
WIRE 304 128 304 96
WIRE 304 128 256 128
WIRE 16 160 16 128
WIRE 224 176 224 160
WIRE -80 256 -80 192
WIRE 16 256 16 224
WIRE 16 256 -80 256
WIRE 32 256 16 256
WIRE 224 272 224 256
WIRE 224 272 144 272
WIRE 240 272 224 272
WIRE -80 288 -80 256
WIRE 16 288 16 256
WIRE 32 288 16 288
WIRE 16 320 16 288
WIRE -80 400 -80 352
WIRE 16 400 16 384
WIRE 16 400 -80 400
WIRE 96 400 16 400
WIRE 128 400 96 400
WIRE 224 400 192 400
WIRE 224 432 224 400
FLAG 224 432 0
FLAG 240 272 Out
IOPIN 240 272 Out
FLAG 96 400 Ramp
SYMBOL Dig_Add\\CD4xxx\\cd4093b 80 208 R0
WINDOW 0 -17 15 Left 0
WINDOW 3 38 90 Left 0
SYMATTR InstName U1
SYMATTR SpiceLine VDD={Vdd}  SPEED=1.0  TRIPDT=5e-9
SYMBOL cap 128 416 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName Ct
SYMATTR Value 1n
SYMATTR SpiceLine Rpar=1e9
SYMBOL diode -96 288 R0
WINDOW 0 36 35 Left 0
WINDOW 3 20 62 Left 0
SYMATTR InstName D3
SYMATTR Value 1N914
SYMBOL diode 32 384 R180
WINDOW 0 -22 61 Left 0
WINDOW 3 -81 32 Left 0
SYMATTR InstName D4
SYMATTR Value 1N914
SYMBOL Robertugo\\Pote 288 144 M270
WINDOW 0 -9 93 VRight 0
WINDOW 3 31 107 VRight 0
WINDOW 123 -19 -23 VCenter 0
SYMATTR InstName Duty
SYMATTR Value Rt=1e5
SYMATTR Value2 Set={Cursor}
SYMBOL diode -96 128 R0
WINDOW 0 36 35 Left 0
WINDOW 3 20 62 Left 0
SYMATTR InstName D1
SYMATTR Value 1N914
SYMBOL res 240 272 R180
WINDOW 0 36 76 Left 0
WINDOW 3 36 40 Left 0
SYMATTR InstName Rf1
SYMATTR Value 10k
SYMBOL diode 32 224 R180
WINDOW 0 -22 61 Left 0
WINDOW 3 -81 32 Left 0
SYMATTR InstName D2
SYMATTR Value 1N914
TEXT 404 426 Left 0 !.tran 1m uic
TEXT 400 120 Left 0 !.params: Vdd 12\n.step param Cursor 0 .99 .33\n.meas tran ta FIND time WHEN V(out)={Vdd/2} td=.2m rise=1\n.meas tran tb FIND time WHEN V(out)={Vdd/2} td=.2m rise=11\n.meas tran Frec PARAM 10/(tb-ta)\n.Meas tran Tc FIND time WHEN V(Out)={Vdd/2} td=.2m fall=1\n.Meas tran Td FIND time WHEN V(Out)={Vdd/2} td=.2m fall=2\n.Meas tran T1 Param  (Tc-Ta)\n.Meas tran T2  Param  (Td-Ta)\n.Meas tran Ton Param If (T1>0, T1, T2)\n.Meas tran Duty% Param  Ton*Frec*100