Version 4
SHEET 1 1348 680
WIRE 336 64 -112 64
WIRE 80 96 48 96
WIRE 336 96 336 64
WIRE 336 96 304 96
WIRE 384 96 352 96
WIRE 528 96 464 96
WIRE 80 160 16 160
WIRE 352 160 352 96
WIRE 352 160 304 160
WIRE 384 160 352 160
WIRE 496 160 464 160
WIRE 80 224 -16 224
WIRE 496 224 496 160
WIRE 496 224 304 224
WIRE -112 288 -112 64
WIRE 80 288 -112 288
WIRE 336 288 304 288
WIRE -112 320 -112 288
WIRE 16 336 16 160
WIRE 496 336 496 224
WIRE 496 336 16 336
WIRE 16 352 16 336
WIRE 336 352 336 288
WIRE 528 352 528 96
WIRE -112 416 -112 400
WIRE -64 416 -112 416
WIRE -112 448 -112 416
WIRE -64 464 -64 416
WIRE 16 464 16 416
WIRE 16 464 -64 464
WIRE 48 464 48 96
WIRE 48 464 16 464
WIRE 336 464 336 416
WIRE 336 464 48 464
WIRE 528 464 528 432
WIRE 528 464 336 464
FLAG -112 448 0
FLAG -16 224 Out
SYMBOL voltage -112 304 R0
WINDOW 3 -33 60 Left 0
WINDOW 0 8 6 Left 0
SYMATTR Value {Vdd}
SYMATTR InstName V+
SYMBOL Robertugo\\555_ALL 240 208 R0
WINDOW 38 -81 79 Left 0
SYMATTR InstName U1
SYMBOL cap 0 352 R0
WINDOW 0 -29 9 Left 0
WINDOW 3 -35 52 Left 0
SYMATTR InstName C1
SYMATTR Value 1n
SYMBOL res 480 144 R90
WINDOW 0 15 95 VBottom 0
WINDOW 3 -12 10 VTop 0
SYMATTR InstName R1
SYMATTR Value 10k
SYMBOL cap 320 352 R0
WINDOW 0 -29 8 Left 0
WINDOW 3 -31 56 Left 0
SYMATTR InstName C2
SYMATTR Value .1µ
SYMBOL res 480 80 R90
WINDOW 0 14 113 VBottom 0
WINDOW 3 -15 14 VTop 0
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL voltage 528 336 R0
WINDOW 3 -92 101 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
WINDOW 0 -26 58 Left 0
SYMATTR Value {Vctrl}
SYMATTR InstName Vctrl
TEXT 606 88 Left 0 !.tran 0 3m 1m 400u startup
TEXT 600 112 Left 0 !.params: Vdd 12 Ronx=.1 \n.step param Vctrl 8 12 1 \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