Version 4 SHEET 1 10964 10608 WIRE 6000 3456 5968 3456 WIRE 6112 3456 6080 3456 WIRE 5216 3536 4928 3536 WIRE 5328 3536 5280 3536 WIRE 5424 3536 5328 3536 WIRE 5504 3536 5424 3536 WIRE 5616 3536 5504 3536 WIRE 5760 3536 5616 3536 WIRE 5792 3536 5760 3536 WIRE 5904 3536 5872 3536 WIRE 5968 3536 5968 3456 WIRE 5968 3536 5904 3536 WIRE 6096 3536 5968 3536 WIRE 6432 3536 6192 3536 WIRE 6576 3536 6432 3536 WIRE 6704 3536 6576 3536 WIRE 6928 3536 6784 3536 WIRE 7072 3536 6928 3536 WIRE 7312 3536 7072 3536 WIRE 7504 3536 7408 3536 WIRE 7632 3536 7504 3536 WIRE 7664 3536 7632 3536 WIRE 7776 3536 7744 3536 WIRE 7824 3536 7776 3536 WIRE 7872 3536 7824 3536 WIRE 7984 3536 7872 3536 WIRE 4928 3552 4928 3536 WIRE 5328 3552 5328 3536 WIRE 5968 3552 5968 3536 WIRE 7504 3552 7504 3536 WIRE 7872 3552 7872 3536 WIRE 7984 3552 7984 3536 WIRE 6576 3568 6576 3536 WIRE 6928 3568 6928 3536 WIRE 6176 3632 6176 3584 WIRE 4928 3648 4928 3632 WIRE 5328 3648 5328 3616 WIRE 5968 3648 5968 3616 WIRE 6528 3648 6512 3648 WIRE 6992 3648 6976 3648 WIRE 7504 3648 7504 3616 WIRE 7872 3648 7872 3616 WIRE 7984 3648 7984 3616 WIRE 6576 3696 6576 3664 WIRE 6752 3696 6576 3696 WIRE 6928 3696 6928 3664 WIRE 6928 3696 6752 3696 WIRE 6752 3712 6752 3696 WIRE 6752 3712 6688 3712 WIRE 6752 3728 6752 3712 WIRE 7984 3744 7984 3712 WIRE 6992 3760 6992 3648 WIRE 6752 3824 6752 3808 WIRE 6816 3824 6752 3824 WIRE 6752 3840 6752 3824 WIRE 7984 3840 7984 3808 WIRE 7392 3888 6304 3888 WIRE 7600 3888 7456 3888 WIRE 7984 3936 7984 3904 WIRE 6304 3952 6304 3888 WIRE 6336 3952 6304 3952 WIRE 6432 3952 6432 3536 WIRE 6432 3952 6400 3952 WIRE 6512 3952 6512 3648 WIRE 6560 3952 6512 3952 WIRE 6992 3952 6992 3840 WIRE 6992 3952 6944 3952 WIRE 7072 3952 7072 3536 WIRE 7120 3952 7072 3952 WIRE 7200 3952 7184 3952 WIRE 7504 3952 7200 3952 WIRE 7600 3952 7600 3888 WIRE 7600 3952 7568 3952 WIRE 6176 4000 6176 3712 WIRE 6304 4000 6304 3952 WIRE 6432 4000 6432 3952 WIRE 6560 4000 6560 3952 WIRE 6688 4000 6688 3712 WIRE 6816 4000 6816 3824 WIRE 6944 4000 6944 3952 WIRE 7072 4000 7072 3952 WIRE 7200 4000 7200 3952 WIRE 7328 4000 7328 3584 WIRE 7984 4032 7984 4000 WIRE 5904 4064 5904 3536 WIRE 6128 4064 5904 4064 WIRE 7632 4064 7632 3536 WIRE 7632 4064 7376 4064 WIRE 7984 4112 7984 4096 WIRE 5760 4128 5760 3536 WIRE 6128 4128 5760 4128 WIRE 7456 4128 7376 4128 WIRE 7776 4128 7776 3536 WIRE 7776 4128 7456 4128 WIRE 7600 4144 7600 3952 WIRE 5504 4160 5504 3536 WIRE 7824 4160 7824 3536 WIRE 5616 4192 5616 3536 WIRE 6128 4192 5616 4192 WIRE 7456 4192 7456 4128 WIRE 7456 4192 7376 4192 WIRE 5504 4256 5504 4240 WIRE 6128 4256 5504 4256 WIRE 7824 4256 7824 4240 WIRE 7824 4256 7376 4256 WIRE 5504 4272 5504 4256 WIRE 7824 4272 7824 4256 WIRE 5616 4288 5616 4192 WIRE 5920 4320 5824 4320 WIRE 6128 4320 5920 4320 WIRE 7600 4320 7600 4224 WIRE 7600 4320 7376 4320 WIRE 5504 4368 5504 4352 WIRE 5616 4368 5616 4352 WIRE 5760 4368 5616 4368 WIRE 7824 4368 7824 4352 WIRE 5616 4384 5616 4368 WIRE 5920 4384 5920 4320 WIRE 5936 4384 5920 4384 WIRE 6032 4384 6016 4384 WIRE 6128 4384 6032 4384 WIRE 7600 4384 7600 4320 WIRE 7600 4384 7376 4384 WIRE 5424 4400 5424 3536 WIRE 6032 4400 6032 4384 WIRE 7600 4400 7600 4384 WIRE 5824 4432 5824 4416 WIRE 6128 4448 6112 4448 WIRE 7392 4448 7376 4448 WIRE 5616 4480 5616 4464 WIRE 6032 4480 6032 4464 WIRE 7600 4480 7600 4464 WIRE 5424 4512 5424 4480 WIRE 6128 4512 5424 4512 WIRE 7392 4512 7376 4512 WIRE 5424 4544 5424 4512 WIRE 5968 4576 5952 4576 WIRE 6128 4576 6048 4576 WIRE 7392 4576 7376 4576 WIRE 5424 4640 5424 4624 WIRE 6048 4640 6032 4640 WIRE 6128 4640 6112 4640 WIRE 7392 4640 7376 4640 WIRE 5920 4704 5872 4704 WIRE 6032 4704 6000 4704 WIRE 6128 4704 6032 4704 WIRE 7600 4704 7376 4704 WIRE 7696 4704 7600 4704 WIRE 5872 4720 5872 4704 WIRE 6032 4720 6032 4704 WIRE 7600 4720 7600 4704 WIRE 7696 4720 7696 4704 WIRE 7408 4768 7376 4768 WIRE 7504 4768 7408 4768 WIRE 7408 4784 7408 4768 WIRE 7504 4784 7504 4768 WIRE 5872 4800 5872 4784 WIRE 6032 4800 6032 4784 WIRE 6384 4816 6384 4800 WIRE 6704 4816 6704 4800 WIRE 7072 4816 7072 4800 WIRE 7600 4816 7600 4800 WIRE 7696 4816 7696 4784 WIRE 7408 4880 7408 4864 WIRE 7504 4880 7504 4848 FLAG 4928 3536 IN FLAG 5504 4368 0 FLAG 5952 4576 0 FLAG 6032 4640 0 FLAG 6032 4800 0 FLAG 5872 4800 0 FLAG 6384 4816 0 FLAG 6752 3840 0 FLAG 7984 3536 SCAPS FLAG 7504 3648 0 FLAG 7824 4368 0 FLAG 4928 3648 0 FLAG 7872 3648 0 FLAG 6112 4448 0 FLAG 7072 4816 0 FLAG 5328 3648 0 FLAG 7600 4480 0 FLAG 5968 3648 0 FLAG 6112 3456 0 FLAG 5424 4640 0 FLAG 6032 4480 0 FLAG 5616 4480 0 FLAG 5824 4432 0 FLAG 7408 4880 0 FLAG 7504 4880 0 FLAG 7600 4816 0 FLAG 7696 4816 0 FLAG 7984 4112 0 FLAG 5968 3456 LOAD SYMBOL LT8705 6704 4400 R0 SYMATTR InstName U1 SYMBOL voltage 4928 3536 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value PWL(0 0 20u 12 3.5m 12 3.6m 0) SYMBOL cap 5312 3552 R0 WINDOW 3 38 32 Left 2 WINDOW 123 24 57 Left 2 SYMATTR Value 100µ SYMATTR Value2 x2 SYMATTR InstName C1 SYMATTR SpiceLine Rser=30m SYMBOL res 6160 3616 R0 SYMATTR InstName R1 SYMATTR Value 2 SYMBOL res 6976 3744 R0 SYMATTR InstName R2 SYMATTR Value 2 SYMBOL res 6736 3712 R0 SYMATTR InstName R3 SYMATTR Value 3m SYMBOL cap 6400 3936 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C2 SYMATTR Value 0.22µ SYMBOL cap 7184 3936 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C3 SYMATTR Value 0.22µ SYMBOL res 7808 4144 R0 SYMATTR InstName R4 SYMATTR Value 115K SYMBOL res 7808 4256 R0 SYMATTR InstName R5 SYMATTR Value 10K SYMBOL res 7584 4128 R0 SYMATTR InstName R6 SYMATTR Value 4 SYMBOL cap 7584 4400 R0 WINDOW 3 38 33 Left 2 WINDOW 123 25 57 Left 2 SYMATTR Value 4.7µ SYMATTR Value2 x2 SYMATTR InstName C4 SYMBOL res 5920 4400 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R7 SYMATTR Value 100K SYMBOL res 5488 4256 M180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R8 SYMATTR Value 71.5K SYMBOL res 5488 4256 R0 SYMATTR InstName R9 SYMATTR Value 20K SYMBOL res 5952 4592 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R10 SYMATTR Value 124K SYMBOL cap 5856 4720 R0 SYMATTR InstName C5 SYMATTR Value 15n SYMBOL res 6016 4688 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R11 SYMATTR Value 14.3K SYMBOL cap 6016 4720 R0 SYMATTR InstName C6 SYMATTR Value 220p SYMBOL cap 6112 4656 M270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName C7 SYMATTR Value 5n SYMBOL nmos 6096 3584 R270 WINDOW 0 55 48 VTop 2 WINDOW 3 -18 68 VLeft 2 SYMATTR InstName Q1 SYMATTR Value IRLR2908 SYMBOL ind 6688 3552 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 5 56 VBottom 2 SYMATTR InstName L1 SYMATTR Value 2.2µ SYMATTR SpiceLine Rser=14.6m SYMBOL nmos 6528 3568 R0 SYMATTR InstName Q2 SYMATTR Value IRLR2908 SYMBOL nmos 6976 3568 M0 SYMATTR InstName Q3 SYMATTR Value IRLR2908 SYMBOL nmos 7408 3584 M270 WINDOW 0 60 41 VTop 2 WINDOW 3 -24 75 VLeft 2 SYMATTR InstName Q4 SYMATTR Value IRLR2908 SYMBOL schottky 7456 3904 M270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D1 SYMATTR Value MBRS1100 SYMATTR Description Diode SYMATTR Type diode SYMBOL schottky 7568 3968 M270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D2 SYMATTR Value MBRS1100 SYMATTR Description Diode SYMATTR Type diode SYMBOL cap 5952 3552 R0 WINDOW 3 37 31 Left 2 WINDOW 123 24 57 Left 2 SYMATTR Value 22µ SYMATTR Value2 x3 SYMATTR InstName C8 SYMATTR SpiceLine Rser=0.003 SYMBOL res 5776 3552 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R12 SYMATTR Value 25m SYMBOL res 5408 4384 R0 SYMATTR InstName R13 SYMATTR Value 113K SYMBOL res 5408 4528 R0 SYMATTR InstName R14 SYMATTR Value 20K SYMBOL cap 6016 4400 R0 SYMATTR InstName C9 SYMATTR Value 4.7µ SYMBOL zener 5600 4352 M180 WINDOW 0 24 64 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D3 SYMATTR Value BZX84C15L SYMATTR Description Diode SYMATTR Type diode SYMBOL res 5600 4368 R0 SYMATTR InstName R15 SYMATTR Value 1K SYMBOL npn 5760 4320 R0 SYMATTR InstName Q5 SYMATTR Value 2N3904 SYMBOL schottky 5216 3552 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D4 SYMATTR Value SS24 SYMATTR Description Diode SYMATTR Type diode SYMBOL cap 7856 3552 R0 WINDOW 3 38 32 Left 2 WINDOW 123 24 57 Left 2 SYMATTR Value 100µ SYMATTR Value2 x2 SYMATTR InstName C10 SYMATTR SpiceLine Rser=30m SYMBOL cap 7488 3552 R0 WINDOW 3 37 31 Left 2 WINDOW 123 24 57 Left 2 SYMATTR Value 22µ SYMATTR Value2 x3 SYMATTR InstName C11 SYMATTR SpiceLine Rser=0.003 SYMBOL res 7648 3552 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R16 SYMATTR Value 25m SYMBOL res 7392 4768 R0 SYMATTR InstName R17 SYMATTR Value 47.5K SYMBOL res 7584 4704 R0 SYMATTR InstName R18 SYMATTR Value 24K SYMBOL cap 7488 4784 R0 SYMATTR InstName C12 SYMATTR Value 100n SYMBOL cap 7680 4720 R0 SYMATTR InstName C13 SYMATTR Value 100n SYMBOL cap 7968 3552 R0 WINDOW 3 37 33 Left 2 WINDOW 39 24 56 Left 2 SYMATTR Value 3m SYMATTR SpiceLine Rpar=1.2K SYMATTR InstName C14 SYMBOL cap 7968 3648 R0 WINDOW 3 39 34 Left 2 WINDOW 39 25 60 Left 2 SYMATTR Value 3m SYMATTR SpiceLine Rpar=1.2K SYMATTR InstName C15 SYMBOL cap 7968 3744 R0 WINDOW 3 39 34 Left 2 WINDOW 39 25 60 Left 2 SYMATTR Value 3m SYMATTR SpiceLine Rpar=1.2K SYMATTR InstName C16 SYMBOL cap 7968 3840 R0 WINDOW 3 39 34 Left 2 WINDOW 39 25 60 Left 2 SYMATTR Value 3m SYMATTR SpiceLine Rpar=1.2K SYMATTR InstName C17 SYMBOL cap 7968 3936 R0 WINDOW 3 39 34 Left 2 WINDOW 39 25 60 Left 2 SYMATTR Value 3m SYMATTR SpiceLine Rpar=1.2K SYMATTR InstName C18 SYMBOL cap 7968 4032 R0 WINDOW 3 39 34 Left 2 WINDOW 39 25 60 Left 2 SYMATTR Value 3m SYMATTR SpiceLine Rpar=1.2K SYMATTR InstName C19 SYMBOL res 5984 3472 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName Rload SYMATTR Value 12 TEXT 7600 4888 Left 2 !.tran 5.5m startup TEXT 6856 3480 Bottom 2 ;LT8705 - 80V Vin and Vout Synchronous 4-Switch Buck- Boost DC/DC Controller\nBi-Directional Buck-Boost Supercapacitor Backup Supply\nInput: 36V to 80V Output: SCAPs 15V @ 1A, Load Holdup 8V @ 4A TEXT 6008 4880 Left 2 ;Note:\n A smaller SS capacitor, C7, and SCAPS are being used to reduce simulation time. Typical SS capacitor value should be 1µF.\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 © 2015 Linear Technology Inc. All rights reserved.