Version 4
SHEET 1 1536 680
WIRE -304 400 -304 16
WIRE -304 464 -304 400
WIRE -288 336 -288 80
WIRE -272 288 -272 144
WIRE -272 400 -304 400
WIRE -272 416 -272 400
WIRE -256 240 -256 208
WIRE -240 16 -304 16
WIRE -240 80 -288 80
WIRE -240 144 -272 144
WIRE -240 208 -256 208
WIRE -208 288 -272 288
WIRE -112 368 -112 304
WIRE -112 464 -304 464
WIRE -112 464 -112 448
WIRE 0 16 -16 16
WIRE 0 16 0 -32
WIRE 16 144 -16 144
WIRE 16 192 16 144
WIRE 32 208 -16 208
WIRE 32 304 -112 304
WIRE 32 304 32 208
WIRE 176 -32 0 -32
WIRE 176 -16 176 -32
WIRE 176 80 -16 80
WIRE 176 80 176 64
WIRE 176 96 176 80
WIRE 176 192 16 192
WIRE 176 192 176 176
WIRE 176 336 -288 336
WIRE 176 336 176 192
WIRE 176 384 176 336
WIRE 176 464 -112 464
WIRE 176 464 176 448
WIRE 224 -32 176 -32
WIRE 224 240 -256 240
WIRE 224 240 224 -32
WIRE 304 -32 224 -32
WIRE 304 288 304 -32
WIRE 304 464 176 464
WIRE 304 464 304 368
FLAG -208 288 Out555
FLAG 32 304 Pwm
IOPIN 32 304 In
FLAG -272 416 0
SYMBOL cap 160 384 R0
WINDOW 0 70 30 Right 0
WINDOW 3 76 60 Right 0
SYMATTR InstName Ct
SYMATTR Value 470p
SYMBOL res 192 80 R180
WINDOW 0 36 76 Left 0
WINDOW 3 36 40 Left 0
SYMATTR InstName Rt0
SYMATTR Value 1k
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL 555_ALL -80 128 R0
WINDOW 38 -86 79 Left 0
SYMATTR InstName U1
SYMBOL voltage 304 272 R0
WINDOW 0 -32 2 Left 0
WINDOW 3 -29 60 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 -83 109 Left 0
SYMATTR InstName V1
SYMATTR Value {Vdd}
SYMBOL voltage -112 352 R0
WINDOW 0 -26 60 Left 0
WINDOW 3 39 57 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 -83 109 Left 0
SYMATTR InstName Vctrl
SYMATTR Value {Vpwm}
SYMBOL res 160 80 R0
WINDOW 0 -33 37 Left 0
WINDOW 3 -34 69 Left 0
SYMATTR InstName Rt1
SYMATTR Value 1e5
TEXT -226 -30 Left 0 !.tran 3m startup
TEXT 320 -16 Left 0 !.params: Vdd 12 Ronx=.1\n.step param Vpwm List 0.4 1 2 3 4 5 6 7\n.meas tran ta FIND time WHEN V(out555)={Vdd/2} td=1m rise=1\n.meas tran tb FIND time WHEN V(out555)={Vdd/2} td=1m rise=11\n.meas tran Frec PARAM 10/(tb-ta)\n.Meas tran Tc FIND time WHEN V(Out555)={Vdd/2} td=1m fall=1\n.Meas tran Td FIND time WHEN V(Out555)={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