Add PWM Control and Increase Stability

Add voltage sources to control Analog and Digital dimming.
Change compensation network to stop overshoot on startup.

DC_DC_Boost.asc

@@ -1,28 +1,31 @@
 Version 4
 SHEET 1 2684 1812
-WIRE -992 -112 -1104 -112
-WIRE -800 -112 -992 -112
-WIRE -16 -112 -800 -112
+WIRE -992 -352 -1104 -352
+WIRE -800 -352 -992 -352
+WIRE -16 -352 -800 -352
+WIRE -1104 -336 -1104 -352
+WIRE -992 -336 -992 -352
+WIRE -800 -336 -800 -352
+WIRE -992 -256 -992 -272
+WIRE -1104 -240 -1104 -256
+WIRE -800 -224 -800 -256
+WIRE -208 -224 -800 -224
+WIRE -16 -112 -16 -352
 WIRE 224 -112 -16 -112
 WIRE 480 -112 304 -112
 WIRE 592 -112 480 -112
 WIRE 752 -112 656 -112
 WIRE 992 -112 752 -112
 WIRE 1088 -112 992 -112
-WIRE -1104 -96 -1104 -112
-WIRE -992 -96 -992 -112
-WIRE -800 -96 -800 -112
+WIRE -800 -96 -800 -144
 WIRE -16 -64 -16 -112
 WIRE 992 -64 992 -112
-WIRE -992 -16 -992 -32
 WIRE 480 -16 480 -112
-WIRE -1104 0 -1104 -16
-WIRE -800 0 -800 -16
-WIRE -192 0 -800 0
+WIRE -208 0 -208 -224
+WIRE -192 0 -208 0
 WIRE 224 0 160 0
 WIRE 272 0 224 0
 WIRE 352 0 336 0
-WIRE -800 16 -800 0
 WIRE 352 16 352 0
 WIRE 752 16 752 -112
 WIRE -304 64 -352 64
@@ -31,42 +34,44 @@ WIRE 432 64 160 64
 WIRE 992 64 992 16
 WIRE 992 64 896 64
 WIRE 992 80 992 64
-WIRE -800 128 -800 96
-WIRE -704 128 -800 128
-WIRE -592 128 -624 128
-WIRE -464 128 -592 128
+WIRE -864 128 -1040 128
+WIRE -720 128 -784 128
+WIRE -464 128 -640 128
 WIRE -192 128 -384 128
 WIRE 480 128 480 80
 WIRE 480 128 160 128
-WIRE -800 144 -800 128
-WIRE -592 192 -592 128
-WIRE -192 192 -592 192
+WIRE -1040 160 -1040 128
+WIRE -192 192 -1056 192
 WIRE 992 192 992 160
 WIRE 752 208 752 80
 WIRE 752 208 480 208
 WIRE 480 224 480 208
-WIRE -192 256 -1040 256
+WIRE -192 256 -752 256
 WIRE 896 256 896 64
 WIRE 896 256 160 256
 WIRE 1088 304 1088 -112
 WIRE 1088 304 960 304
-WIRE -1040 320 -1040 256
-WIRE -192 320 -736 320
+WIRE -752 320 -752 256
+WIRE -192 320 -624 320
 WIRE 960 320 960 304
 WIRE 960 320 160 320
-WIRE -736 368 -736 320
-WIRE -192 384 -464 384
+WIRE -624 368 -624 320
+WIRE -192 384 -384 384
 WIRE 1088 384 160 384
-WIRE -464 400 -464 384
-WIRE -1040 416 -1040 400
+WIRE -1056 400 -1056 192
+WIRE -384 400 -384 384
+WIRE -752 416 -752 400
 WIRE -192 448 -256 448
 WIRE 224 448 160 448
-WIRE -1040 496 -1040 480
-WIRE -736 496 -736 432
-WIRE -736 496 -1040 496
-WIRE -464 496 -464 480
-WIRE -464 496 -736 496
-WIRE -736 528 -736 496
+WIRE -256 464 -256 448
+WIRE -1056 496 -1056 480
+WIRE -752 496 -752 480
+WIRE -624 496 -624 432
+WIRE -624 496 -752 496
+WIRE -384 496 -384 480
+WIRE -384 496 -624 496
+WIRE -624 528 -624 496
+WIRE -256 560 -256 544
 WIRE 688 576 320 576
 WIRE 1024 576 752 576
 WIRE 688 608 688 576
@@ -80,6 +85,7 @@ WIRE 688 736 688 672
 WIRE 752 736 752 672
 WIRE 1024 736 1024 672
 WIRE 1088 736 1088 672
+WIRE -848 768 -848 752
 WIRE -16 800 -16 512
 WIRE 320 800 320 736
 WIRE 320 800 -16 800
@@ -102,32 +108,34 @@ WIRE 752 1216 688 1216
 WIRE 1024 1216 1024 1184
 WIRE 1088 1216 1088 1184
 WIRE 1088 1216 1024 1216
-FLAG -1104 0 0
-FLAG -992 -16 0
+FLAG -1104 -240 0
+FLAG -992 -256 0
 FLAG 352 16 0
 FLAG 992 192 0
-FLAG -736 528 0
-FLAG -256 448 INTVcc
+FLAG -624 528 0
 FLAG -352 64 INTVcc
-FLAG -800 144 0
+FLAG -800 -96 0
 FLAG 224 0 INTVcc
 FLAG 480 224 0
 FLAG -16 816 0
+FLAG -256 560 0
+FLAG -1040 160 0
+FLAG -1056 496 0
 SYMBOL PowerProducts\\LT3761 -16 224 R0
 SYMATTR InstName U1
-SYMBOL voltage -1104 -112 R0
+SYMBOL voltage -1104 -352 R0
 WINDOW 123 0 0 Left 2
 WINDOW 39 0 0 Left 2
 SYMATTR InstName V1
 SYMATTR Value 12
-SYMBOL cap -1008 -96 R0
+SYMBOL cap -1008 -336 R0
 SYMATTR InstName C1
 SYMATTR Value 3.3µ
 SYMATTR SpiceLine V=25 Irms=0 Rser=0.005 Lser=0 mfg="TDK" pn="C4532X7RlE335M" type="X7R"
-SYMBOL res -816 -112 R0
+SYMBOL res -816 -352 R0
 SYMATTR InstName R1
 SYMATTR Value 470k
-SYMBOL res -816 0 R0
+SYMBOL res -816 -240 R0
 SYMATTR InstName R2
 SYMATTR Value 68k
 SYMBOL res 1072 288 R0
@@ -197,28 +205,28 @@ SYMBOL res -368 112 R90
 WINDOW 0 0 56 VBottom 2
 WINDOW 3 32 56 VTop 2
 SYMATTR InstName R4
-SYMATTR Value 4.7k
-SYMBOL res -608 112 R90
+SYMATTR Value 8.2k
+SYMBOL res -768 112 R90
 WINDOW 0 0 56 VBottom 2
-WINDOW 3 32 56 VTop 2
+WINDOW 3 42 93 VTop 2
 SYMATTR InstName R5
-SYMATTR Value 10k
+SYMATTR Value {{(1-ADim)*10000}}
 SYMBOL res -320 80 R270
 WINDOW 0 32 56 VTop 2
 WINDOW 3 0 56 VBottom 2
 SYMATTR InstName R6
 SYMATTR Value 100k
-SYMBOL cap -752 368 R0
+SYMBOL cap -640 368 R0
 WINDOW 0 41 18 Left 2
 SYMATTR InstName C2
-SYMATTR Value 20n
-SYMBOL res -480 384 R0
+SYMATTR Value 10n
+SYMBOL res -400 384 R0
 SYMATTR InstName R7
 SYMATTR Value 27k
-SYMBOL cap -1056 416 R0
+SYMBOL cap -768 416 R0
 SYMATTR InstName C3
 SYMATTR Value 4.7n
-SYMBOL res -1056 304 R0
+SYMBOL res -768 304 R0
 SYMATTR InstName R8
 SYMATTR Value 30k
 SYMBOL cap 336 -16 R90
@@ -316,14 +324,30 @@ SYMATTR InstName D20
 SYMATTR Value LUW-W5AP
 SYMATTR Description Diode
 SYMATTR Type diode
-TEXT -888 -192 Left 2 ;EN/UVLO\nR1 and R2 set start to 10.73 V\nand cutout to 9.65 V
-TEXT -632 80 Left 2 ;1.36 V to enable\nfull LED current
-TEXT -8 1200 Left 2 !.tran 3m startup
+SYMBOL voltage -256 448 R0
+WINDOW 123 0 0 Left 2
+WINDOW 39 0 0 Left 2
+SYMATTR InstName V2
+SYMATTR Value PULSE(0 5 0 1n 1n 1m 2m)
+SYMBOL res -736 144 R270
+WINDOW 0 32 56 VTop 2
+WINDOW 3 -10 76 VBottom 2
+SYMATTR InstName R12
+SYMATTR Value {{ADim}*10000}
+SYMBOL voltage -1056 384 R0
+WINDOW 3 -33 161 Left 2
+WINDOW 123 0 0 Left 2
+WINDOW 39 0 0 Left 2
+SYMATTR Value PULSE(0 1.08 0 15m 1n 0 16m)
+SYMATTR InstName V3
+TEXT -720 -168 Left 2 ;EN/UVLO\nR1 and R2 set start to 10.73 V\nand cutout to 9.65 V
+TEXT -8 1200 Left 2 !.tran 15m startup
 TEXT -1088 880 Left 6 ;Boost Converter\nInput 12 V\nOutput 60 V @ 300 mA\n400 kHz
-TEXT -568 520 Left 2 ;set f to approx\n380 kHz
-TEXT -680 344 Left 2 ;set startup\ntime to 2 ms
-TEXT -1112 496 Left 2 ;loop\ncompensation
-TEXT -328 480 Left 2 ;PWM\nunused
+TEXT -512 520 Left 2 ;set f to approx\n380 kHz
+TEXT -560 352 Left 2 ;set startup\ntime to 2 ms
+TEXT -920 288 Left 2 ;loop\ncompensation
 TEXT -376 32 Left 2 ;pull-up
 TEXT 816 -72 Left 2 ;output voltage\nlimit set to\n66.17 V
-TEXT 888 416 Left 2 ;set LED current\nto 304 mA
+TEXT -864 64 Left 2 !.PARAM ADim=0.01
+TEXT -864 8 Left 2 ;10k Potentiometer
+RECTANGLE Normal -544 224 -992 32 2

DC_DC_Boost.plt

@@ -0,0 +1,14 @@
+[Transient Analysis]
+{
+   Npanes: 1
+   {
+      traces: 4 {524293,2,"V(N016,N025)*I(D1)*20"} {524292,0,"V(n012)"} {524290,0,"V(N016,N020)"} {303038467,1,"I(D1)"}
+      X: ('m',0,0,0.001,0.015)
+      Y[0]: (' ',0,0,6,60)
+      Y[1]: (' ',2,0,0.05,0.4)
+      Volts: (' ',0,0,0,0,6,60)
+      Amps: (' ',0,0,2,0,0.05,0.4)
+      Units: "W" (' ',0,0,0,0,2,20)
+      Log: 0 0 0
+   }
+}