Version 4
SHEET 1 936 680
WIRE -48 -64 -208 -64
WIRE 400 -64 -48 -64
WIRE -208 -48 -208 -64
WIRE -48 -48 -48 -64
WIRE -208 48 -208 32
WIRE -48 48 -48 32
WIRE 80 48 -48 48
WIRE 400 48 400 -64
WIRE 400 48 368 48
WIRE -48 64 -48 48
WIRE 80 144 64 144
WIRE 592 144 368 144
WIRE -48 160 -48 144
WIRE 0 240 -32 240
WIRE 80 240 64 240
WIRE 400 240 368 240
WIRE 400 256 400 240
WIRE -16 336 -32 336
WIRE 80 336 64 336
WIRE 400 336 400 320
WIRE 400 336 368 336
WIRE 480 336 400 336
WIRE 592 336 592 144
WIRE 592 336 560 336
WIRE 704 336 592 336
WIRE 800 336 704 336
WIRE 400 352 400 336
WIRE 592 352 592 336
WIRE 800 352 800 336
WIRE 704 368 704 336
WIRE 80 432 64 432
WIRE 592 432 368 432
WIRE 400 448 400 416
WIRE 592 448 592 432
WIRE 704 448 704 432
WIRE 800 448 800 432
WIRE 592 544 592 528
FLAG 64 432 0
FLAG -32 336 0
FLAG 800 448 0
FLAG 704 448 0
FLAG 592 544 0
FLAG -208 48 0
FLAG 400 448 0
FLAG -48 160 0
FLAG -32 240 0
FLAG -208 -64 IN
FLAG 800 336 OUT
SYMBOL res 80 320 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 118K
SYMBOL res 576 432 R0
SYMATTR InstName R2
SYMATTR Value 562K
SYMBOL ind 464 352 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName L1
SYMATTR Value 4.7µ
SYMBOL res 576 336 R0
SYMATTR InstName R3
SYMATTR Value 1Meg
SYMBOL cap 688 368 R0
SYMATTR InstName C1
SYMATTR Value 22µ
SYMBOL res 784 336 R0
SYMATTR InstName Rout
SYMATTR Value 2.75
SYMBOL voltage -208 -64 R0
SYMATTR InstName V1
SYMATTR Value 12
SYMBOL schottky 384 416 M180
WINDOW 0 26 68 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D1
SYMATTR Value DFLS220L
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL cap 384 256 R0
WINDOW 3 24 54 Left 2
SYMATTR Value .47µ
SYMATTR InstName C2
SYMBOL res -64 48 R0
SYMATTR InstName R5
SYMATTR Value 1Meg
SYMBOL res -64 -64 R0
SYMATTR InstName R6
SYMATTR Value 5Meg
SYMBOL cap 64 224 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C3
SYMATTR Value .001µ
SYMBOL PowerProducts\\LT3991 224 240 R0
SYMATTR InstName U1
TEXT 720 536 Left 2 !.tran 1.5m startup