Version 4
SHEET 1 1256 680
WIRE -112 112 -144 112
WIRE -16 112 -48 112
WIRE 112 112 48 112
WIRE 208 112 176 112
WIRE -144 160 -144 112
WIRE 208 160 208 112
WIRE 208 160 -144 160
WIRE -64 208 -80 208
WIRE 16 208 16 144
WIRE -80 256 -80 208
WIRE 16 256 -80 256
WIRE 32 256 16 256
WIRE 208 272 208 160
WIRE 208 272 144 272
WIRE 224 272 208 272
WIRE -80 288 -80 256
WIRE 32 288 -80 288
WIRE -80 304 -80 288
WIRE -80 384 -80 368
FLAG -80 384 0
FLAG 224 272 Out
FLAG 16 256 Tri
SYMBOL Dig_Add\\CD4xxx\\cd4093b 80 208 R0
WINDOW 0 -28 14 Left 0
WINDOW 3 28 46 Left 0
SYMATTR InstName Unand
SYMATTR SpiceLine VDD={Vdd}  SPEED=1.0  TRIPDT=5e-9
SYMBOL cap -96 304 R0
WINDOW 0 37 11 Left 0
WINDOW 3 36 47 Left 0
SYMATTR InstName Ct
SYMATTR Value 1n
SYMATTR SpiceLine Rpar=1e9
SYMBOL res -80 224 R270
WINDOW 0 34 10 VTop 0
WINDOW 3 59 62 VBottom 0
SYMATTR InstName Rf
SYMATTR Value 10k
SYMBOL Robertugo\\pote -48 128 R270
WINDOW 0 30 17 VCenter 0
WINDOW 3 30 135 VCenter 0
WINDOW 123 -48 140 VCenter 0
SYMATTR InstName U1
SYMATTR Value Rt=100K
SYMATTR Value2 Set={cursor}
SYMBOL diode -112 96 M90
WINDOW 0 16 -13 VBottom 0
WINDOW 3 34 16 VTop 0
SYMATTR InstName D3
SYMATTR Value 1N914
SYMBOL diode 112 96 M90
WINDOW 0 16 79 VBottom 0
WINDOW 3 39 26 VTop 0
SYMATTR InstName D4
SYMATTR Value 1N914
TEXT 44 346 Left 0 !.tran 2m uic
TEXT 272 104 Left 0 !.params: Vdd 12\n.step param Cursor 0 .99 .33\n.meas tran ta FIND time WHEN V(out)={Vdd/2} td=1m rise=1\n.meas tran tb FIND time WHEN V(out)={Vdd/2} td=1m rise=11\n.meas tran Frec PARAM 10/(tb-ta)\n.Meas tran Tc FIND time WHEN V(Out)={Vdd/2} td=1m fall=1\n.Meas tran Td FIND time WHEN V(Out)={Vdd/2} td=1m 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