Version 4
SHEET 1 880 680
WIRE -176 96 -192 96
WIRE 96 96 -96 96
WIRE 624 96 320 96
WIRE 624 112 624 96
WIRE 96 176 80 176
WIRE 368 176 320 176
WIRE 512 176 368 176
WIRE 368 192 368 176
WIRE 512 192 512 176
WIRE 624 208 624 192
WIRE 0 256 -16 256
WIRE 96 256 80 256
WIRE 336 256 320 256
WIRE 336 288 336 256
WIRE 368 288 368 272
WIRE 368 288 336 288
WIRE 512 288 512 272
WIRE 368 304 368 288
WIRE 368 400 368 384
FLAG -192 96 0
FLAG 512 288 0
FLAG 624 96 PWMout
FLAG 80 176 0
FLAG -16 256 0
FLAG 624 208 0
FLAG 368 400 0
SYMBOL res 96 240 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 487K
SYMBOL res 352 288 R0
SYMATTR InstName R2
SYMATTR Value 1000K
SYMBOL res 352 176 R0
SYMATTR InstName R3
SYMATTR Value 392K
SYMBOL res 608 96 R0
SYMATTR InstName R4
SYMATTR Value 10K
SYMBOL voltage 512 176 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 3
SYMBOL voltage -80 96 R90
WINDOW 123 74 56 VTop 2
WINDOW 39 53 56 VTop 2
WINDOW 3 32 56 VTop 2
WINDOW 0 -32 56 VBottom 2
SYMATTR Value PULSE(0 1 10m 50m 50m 5m 110m)
SYMATTR InstName V2
SYMBOL SpecialFunctions\\LTC6992-3 208 176 R0
SYMATTR InstName U1
TEXT 504 384 Left 2 !.tran 120m startup
TEXT 208 56 Bottom 2 ;400Hz, 100% to 5% Duty Cycle\nSwept Pulse Width Modulated Output\nStartup Modeled