Version 4
SHEET 1 880 680
WIRE 64 64 -48 64
WIRE 224 64 64 64
WIRE 224 112 224 64
WIRE -48 144 -48 64
WIRE 112 160 64 160
WIRE 160 160 112 160
WIRE 336 160 288 160
WIRE 416 160 336 160
WIRE 64 176 64 160
WIRE 416 176 416 160
WIRE -48 288 -48 224
WIRE 64 288 64 256
WIRE 64 288 -48 288
WIRE 416 288 416 256
WIRE 416 288 64 288
WIRE 64 304 64 288
FLAG 64 304 0
FLAG 336 160 UL
FLAG 112 160 USW
FLAG 64 64 VDD
SYMBOL voltage -48 128 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName VDD1
SYMATTR Value 5
SYMBOL res 400 160 R0
SYMATTR InstName R1
SYMATTR Value 20
SYMBOL voltage 64 160 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value PULSE(0 5 100n 50n 50n 37u 100u)
SYMBOL stepup1 224 160 R0
WINDOW 0 -23 36 Left 0
SYMATTR InstName ST
TEXT 88 312 Left 0 !.include C:/Programs/LTspiceIV/lib/sub/GFlev8.sub
TEXT 344 80 Left 0 !.tran 0 500u 0
TEXT 344 104 Left 0 !.ic V(UL)=12