Version 4 SHEET 1 2312 1056 WIRE 32 -64 -144 -64 WIRE 496 -64 32 -64 WIRE 544 -64 496 -64 WIRE 640 -64 544 -64 WIRE -144 -48 -144 -64 WIRE 544 -48 544 -64 WIRE 640 -48 640 -64 WIRE 32 -16 32 -64 WIRE 64 -16 32 -16 WIRE 336 -16 288 -16 WIRE 384 -16 336 -16 WIRE 464 -16 448 -16 WIRE 336 0 336 -16 WIRE 544 32 544 16 WIRE 640 32 640 16 WIRE -144 48 -144 32 WIRE -16 80 -32 80 WIRE 64 80 48 80 WIRE 336 80 336 64 WIRE 336 80 288 80 WIRE 496 96 496 -64 WIRE -96 176 -128 176 WIRE 64 176 -32 176 WIRE 448 176 288 176 WIRE 336 192 336 80 WIRE 64 272 -80 272 WIRE 336 272 336 256 WIRE 336 272 288 272 WIRE 496 272 496 192 WIRE 496 272 336 272 WIRE 560 272 496 272 WIRE 704 272 640 272 WIRE 816 272 784 272 WIRE 864 272 816 272 WIRE 976 272 864 272 WIRE 1088 272 976 272 WIRE 1360 272 1088 272 WIRE 1568 272 1504 272 WIRE 1664 272 1568 272 WIRE 496 288 496 272 WIRE 864 288 864 272 WIRE 976 288 976 272 WIRE 1360 304 1360 272 WIRE -160 320 -160 304 WIRE 1136 320 1072 320 WIRE 1568 352 1568 336 WIRE 16 368 -32 368 WIRE 64 368 16 368 WIRE 448 368 288 368 WIRE 864 368 864 352 WIRE 976 368 976 352 WIRE 1664 368 1664 352 WIRE 16 384 16 368 WIRE 1072 384 1072 320 WIRE 1104 384 1072 384 WIRE 1200 384 1168 384 WIRE 1312 384 1264 384 WIRE 496 400 496 384 WIRE -160 416 -160 400 WIRE -80 416 -80 272 WIRE -80 416 -160 416 WIRE 1216 416 1216 320 WIRE 1360 416 1360 400 WIRE 1360 416 1216 416 WIRE 1408 416 1360 416 WIRE 1520 416 1488 416 WIRE 1632 416 1520 416 WIRE -160 432 -160 416 WIRE 1120 432 864 432 WIRE 1632 432 1632 416 WIRE 1072 448 1072 384 WIRE 1088 448 1072 448 WIRE 16 464 16 448 WIRE 64 464 16 464 WIRE 320 464 288 464 WIRE 1200 464 1200 384 WIRE 1200 464 1152 464 WIRE 1264 464 1264 384 WIRE 1264 464 1200 464 WIRE 1088 480 1024 480 WIRE 864 496 864 432 WIRE 1024 496 1024 480 WIRE 1120 512 1120 496 WIRE 1520 512 1520 496 WIRE 1632 512 1632 496 WIRE 16 528 16 464 WIRE 384 528 16 528 WIRE 704 528 704 272 WIRE 704 528 464 528 WIRE -32 576 -32 368 WIRE 192 576 -32 576 WIRE 784 576 784 272 WIRE 784 576 272 576 WIRE 864 592 864 576 WIRE 1024 592 1024 576 WIRE -160 624 -160 512 WIRE 816 624 816 272 WIRE 816 624 -160 624 FLAG 320 464 0 FLAG 496 400 0 FLAG 1520 512 0 FLAG -160 304 0 FLAG 1088 272 OUT FLAG 464 -16 0 FLAG -32 80 0 FLAG -144 48 0 FLAG -144 -64 IN FLAG -128 176 0 FLAG 976 368 0 FLAG 864 368 0 FLAG 544 32 0 FLAG 640 32 0 FLAG 1120 512 0 FLAG 1024 592 0 FLAG 864 592 0 FLAG 1632 512 0 FLAG 1568 352 0 FLAG 1664 368 0 SYMBOL nmos 448 96 R0 SYMATTR InstName Q1 SYMATTR Value RJK0305DPB SYMBOL ind 544 288 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 5 56 VBottom 2 SYMATTR InstName L1 SYMATTR Value 3µH SYMATTR SpiceLine Rser=1.8m SYMBOL res -176 528 M180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R1 SYMATTR Value 200k SYMBOL res -176 416 M180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R2 SYMATTR Value 20K SYMBOL cap 384 0 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName C1 SYMATTR Value 4.7µ SYMBOL cap 48 64 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C2 SYMATTR Value 1n SYMBOL voltage -144 -64 R0 WINDOW 3 20 93 Left 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR Value 19 SYMATTR InstName V1 SYMBOL schottky 320 0 R0 WINDOW 3 22 63 Left 2 SYMATTR Value ZLLS1000 SYMATTR InstName D1 SYMATTR Description Diode SYMATTR Type diode SYMBOL nmos 448 288 R0 SYMATTR InstName Q2 SYMATTR Value RJK0301DPB SYMBOL cap -32 160 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 WINDOW 39 53 32 VTop 2 SYMATTR InstName C3 SYMATTR Value 2.2n SYMATTR SpiceLine Rser=5.62K Cpar=47p SYMBOL PowerProducts\\LTC3854 176 224 R0 SYMATTR InstName U1 SYMBOL cap 320 192 R0 SYMATTR InstName C4 SYMATTR Value .1µ SYMBOL res 800 256 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R3 SYMATTR Value 2m SYMBOL res 288 560 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R4 SYMATTR Value 47 SYMBOL res 480 512 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R5 SYMATTR Value 47 SYMBOL polcap 960 288 R0 WINDOW 123 20 59 Left 2 WINDOW 3 34 34 Left 2 SYMATTR Value 100µ SYMATTR InstName C5 SYMATTR SpiceLine Rser=100m SYMBOL cap 848 288 R0 WINDOW 123 24 60 Left 2 WINDOW 3 39 32 Left 2 SYMATTR Value 100µ SYMATTR InstName C6 SYMATTR SpiceLine Rser=1m SYMBOL polcap 624 -48 R0 SYMATTR InstName C7 SYMATTR Value 180µ SYMATTR SpiceLine V=16 Irms=3.02 Rser=30m SYMBOL cap 528 -48 R0 WINDOW 40 23 61 Left 2 WINDOW 3 36 35 Left 2 SYMATTR SpiceLine2 x3 SYMATTR Value 10µ SYMATTR InstName C8 SYMATTR SpiceLine V=16 Rser=6m SYMBOL cap 0 384 R0 WINDOW 3 29 57 Left 2 WINDOW 39 24 85 Left 2 SYMATTR Value 1n SYMATTR InstName C9 SYMBOL res 1504 400 R0 SYMATTR InstName Rload SYMATTR Value 4 SYMBOL nmos 1312 304 R0 SYMATTR InstName Q3 SYMATTR Value RJK0305DPB SYMBOL voltage 1024 480 R0 WINDOW 3 20 93 Left 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR Value 8.65V SYMATTR InstName V2 SYMBOL Opamps\\LT1208 1120 400 R0 SYMATTR InstName U2 SYMBOL voltage 864 480 R0 WINDOW 3 20 93 Left 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR Value 12V SYMATTR InstName V3 SYMBOL cap 1616 432 R0 WINDOW 123 24 60 Left 2 WINDOW 3 39 32 Left 2 SYMATTR Value 10µ SYMATTR InstName C10 SYMATTR SpiceLine Rser=3m SYMBOL res 1232 304 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R6 SYMATTR Value 1k SYMBOL cap 1168 368 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C11 SYMATTR Value 10p SYMBOL res 1504 400 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R7 SYMATTR Value 10m SYMBOL cap 1552 272 R0 WINDOW 123 24 60 Left 2 WINDOW 3 39 32 Left 2 SYMATTR Value 22µ SYMATTR InstName C12 SYMATTR SpiceLine Rser=4m SYMBOL res 1648 256 R0 SYMATTR InstName Rload1 SYMATTR Value 4 SYMBOL ind 1408 288 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 5 56 VBottom 2 SYMATTR InstName L2 SYMATTR Value 1µH SYMATTR SpiceLine Rser=1.8m TEXT 1248 576 Left 2 !.tran 2m startup TEXT 368 -80 Bottom 2 ;LTC3854 - Small Footprint, Wide Vin Range Synchronous Step-Down DC/DC Controller\nSmall Footprint Step-Down DC-DC Converter\nInput: 4.5V to 14V Output: 1.5V @ 15A, Fsw = 400kHz TEXT -256 624 Left 2 ;Notes:\n Small value is used for the RUN/SS capacitor to reduce simulation time. Typical value should be .1µF.\n More output capacitors may be needed to meet load step and output voltage requirements.\n If the simulation model is not found please update with the "Sync Release" command from the "Tools" menu.\n It remains the customer's responsibility to verify proper and reliable operation in the actual application.\n Component substitution and printed circuit board layout may significantly affect circuit performance or reliability.\n Contact your local sales representative for assistance. This circuit is distributed to customers only for use with LTC parts.\n Copyright © 2012 Linear Technology Inc. All rights reserved.