Version 4 SHEET 1 880 680 WIRE -176 112 -256 112 WIRE -32 112 -96 112 WIRE 96 112 48 112 WIRE 160 112 96 112 WIRE 192 112 160 112 WIRE 368 112 192 112 WIRE 368 144 304 144 WIRE 464 144 432 144 WIRE 160 160 160 112 WIRE -160 176 -160 160 WIRE 96 176 96 112 WIRE -256 192 -256 112 WIRE -112 192 -112 160 WIRE 304 192 304 144 WIRE -256 304 -256 272 WIRE 96 304 96 240 WIRE 160 304 160 240 WIRE 304 304 304 272 FLAG 304 304 0 FLAG -256 304 0 FLAG 96 304 0 FLAG 160 304 0 FLAG -160 176 0 FLAG 464 144 ctr FLAG -112 192 ctr FLAG 192 112 ref SYMBOL Digital\\diffschmitt 368 64 R0 WINDOW 39 13 125 Left 2 SYMATTR InstName A1 SYMATTR SpiceLine Vt=0 Vh=1 vhigh=5 Td=10n SYMBOL voltage 304 176 R0 SYMATTR InstName V1 SYMATTR Value 5 SYMBOL voltage -256 176 R0 SYMATTR InstName V2 SYMATTR Value 10 SYMBOL res -48 128 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R1 SYMATTR Value 100k SYMBOL cap 80 176 R0 SYMATTR InstName C1 SYMATTR Value 1µ SYMBOL res 144 144 R0 SYMATTR InstName R2 SYMATTR Value 5meg SYMBOL sw -192 112 R270 SYMATTR InstName S1 TEXT 8 368 Left 2 !.model sw sw(Ron=1 Roff=100G Vt=2.5) TEXT -232 -80 Left 2 !.tran 0 10 0 1m startup