5 4 R1 20K 2 EXTCLK E1 PLLIN ECO DESCRIPTION DATE APPROVED 2 PROTO 10/24/13 YINGYI, Y. R2 3.01k 1% C46 R4 2.2 R19 R105 OPT OPT CLKOUT VIN 4.7uF VIN OPT 2 C9 OPT TK/SS1 C11 31 4 OPT 5 6 C15 220pF 5 Q4 OPT 4 ITH1 SNSD1+ 220nF 38 VOSNS2+ SNS1- VOSNS2TKSS2 SW2 RUN2 BG2 SNSD2+ 21 TG2 20 SW2 22 BST2 23 BG2 R15 OPT VO_SNS- Q6 OPT R46 10K 1% R47 10K 1% R33 100k 1% R41 OPT CIN4 10uF 1210 4 11 L2 1 2 3 OPT INTVCC1 5 9 C18 0.1uF D2 CMDSH-3-TR 0.25uH Q7 BSC010NE2LSI 4 744301025 DCR=0.32m OHM Q8 OPT 4 R27 3.57k 1% 10 VOUT J5 R28 715 1% VOUT COUT7 100uF 6.3V 1210 COUT6 100uF 6.3V 1210 COUT8 + 330uF 6.3V 7343 COUT5 + 330uF 6.3V 7343 1.0V AT 120A J6 GND 1 2 3 PGOOD R45 5k OPT 17 2 C28 OPT ISNS2- CIN3 10uF 1210 B 19 TRSET1 ENTMPB TRSET2 C27 R48 1 VO_SNS- OPT Q5 BSC050NE2LS C20 220nF FREQ 36 R43 OPT B 1 GND R16 4 TAVG 15 2 C26 SNSA2+ 18 14 TCOMP2 SGND/PGND 13 OPT J4 39 TCOMP1 41 12 RN2 COUT3 + 330uF 6.3V 7343 C R24 0 IFAST 37 RUN OPT COUT4 + 330uF 6.3V 7343 R18 OPT C12 220nF ITH2 TK/SS OPT R9 3.57k 1% COUT2 100uF 6.3V 1210 R14 10 1% 5 VO_SNS- R44 R8 715 1% VOUT COUT1 100uF 6.3V 1210 E7 BOOST2 16 OPT Q3 BSC010NE2LSI 4 40 C10 VFB RN1 J3 CMDSH-3-TR 27 BG1 VOSNS1- TG2 8 4.02k 1% R40 OPT R6 10 1% VOUT VIN 7 C16 2.2nF R21 R13 0 28 BST1 VO_SNSITH VO_SNS+ 1 2 3 VFB BG1 VOSNS1+ INTVCC1 0.1uF D1 0.25uH 744301025 DCR=0.32m OHM 5 32 33 35 LTC3875EUJ#PBF-ES C8 30 SW1 5 R17 20k 1% BOOST1 SNSA1+ 3 VO_SNS+ VO_SNS+ 1 2 3 R12 13.3k 1% ILIM U1 C7 0.1uF SW1 29 TG1 5 TK/SS E3 1 2 3 1 TG1 1 2 3 R100 R11 OPT CIN2 10uF 1210 4 1 2 3 RUN E6 CIN1 10uF 1210 L1 CLKOUT RUN1 PHASMD 34 MODE/PLLIN OPT EXTVCC INTVCC VIN 6 3 R7 E5 TK/SS Q2 OPT 4.7uF C5 10nF 24 2 4 OFF E4 Q1 BSC050NE2LS 5 INTVCC1 C4 26 5 RUN VIN RUN ON GND VIN- R5 1 2 3 SW1 25 J2 C3 1.0uF + C2 270uF 16V 4 1 + C1 270uF 16V 5 D 4.5V - 14V C REV INTVCC1 VIN J1 1 INTVCC1 EXTVCC E2 2 REVISION HISTORY R3 1k VIN+ D 3 MODE PS BM CCM 1 4 JP1 3 INTVCC1 EXTVCC R37 OPT C24 220nF R34 OPT R35 OPT E11 EXTVCC INTVCC1 C25 1.0uF E13 GND R39 OPT R42 100k 1% PGOOD E14 CUSTOMER NOTICE APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. MI VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL YINGTI Y. APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. A THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 4 3 2 TECHNOLOGY 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only TITLE: SCHEMATIC HIGH EFFICIENCY POLYPHASE , SYNCHRONOUS BUCK CONVERTER WITH VERY LOW DCR INDUCTOR SIZE N/A SCALE = NONE PGOOD DATE: IC NO. LTC3875EUJ / LTC3874EUFD DEMO CIRCUIT 2142A 02/26/14 08:23:25 SHEET 1 1 REV. 2 OF 3 A 4 3 INTVCC2 R51 2.2 VIN C29 C30 C31 1.0uF 4.7uF 4.7uF Q10 BSC050NE2LS D Q11 OPT CIN6 10uF 1210 CIN5 10uF 1210 D 4 18 19 20 4 R49 1 EXTVCC 5 VIN 2 5 5 EXTCLK 8 R57 0 4 RUN R60 0 5 28 ITH INTVCC2 LTC3874IUFD#PBF BG0 RUN0 ISENSE0+ 22 BST3 21 BG3 ITH0 ISENSE0- R59 0 1 2 3 1 2 3 C32 INTVCC2 0.1uF D3 744301025 5 Q13 BSC010NE2LSI 4 CMDSH-3-TR COUT12 100uF 6.3V 1210 Q14 OPT 4 R58 715 1% COUT9 100uF 6.3V 1210 COUT10 + 330uF 6.3V 7343 COUT11 + 330uF 6.3V 7343 2 RUN1 3 C33 220nF R63 75k 10 R52 OPT 0 11 FREQ ISENSE1+ ISENSE1- BG4 VIN C 7 6 Q15 BSC050NE2LS C35 220nF 4 FAULT1B GND PHASMD Q16 OPT CIN7 10uF 1210 CIN8 10uF 1210 4 26 L4 25 R65 0 C36 INTVCC2 CMDSH-3-TR R67 0 0 Q17 BSC010NE2LSI 4 Q18 OPT 4 1 2 3 R69 100k 1% R68 0.25uH 744301025 INTVCC2 0.1uF D4 29 OPT R64 17 ILIM FAULT0B 13 BST4 OPT COUT13 100uF 6.3V 1210 5 BG1 16 R62 R66 715 1% COUT14 100uF 6.3V 1210 COUT15 + 330uF 6.3V 7343 COUT16 + 330uF 6.3V 7343 1 2 3 INTVCC2 SW4 5 BOOST1 15 1 2 3 LOWDCR TG4 5 SW1 27 14 5 TG1 ITH1 1 2 3 9 100pF R55 INTVCC2 BOOST0 0 R54 0 R53 U2 MODE1 SW3 R61 C34 OPT MODE0 TG3 23 VOUT 0.25uH 1 2 3 PGOOD SW0 24 5 1 TG0 1 2 3 R56 0 SYNC L3 EXTVCC 12 CLKOUT C INTVCC VIN OPT R50 0 Q19 2N7002A 2 PGOOD 3 R70 OPT B 1 B TK/SS VOUT COUT17 COUT18 + 330uF + 330uF 6.3V 6.3V 7343 7343 COUT19 100uF 6.3V 1210 COUT20 100uF 6.3V 1210 COUT21 1.0uF C40 100uF 6.3V 1210 C39 100uF 6.3V 1210 COUT22 COUT23 + 330uF + 330uF 6.3V 6.3V 7343 7343 COUT25 100uF 6.3V 1210 COUT24 100uF 6.3V 1210 CUSTOMER NOTICE APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. MI VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL YINGTI Y. APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. A THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 4 3 2 TECHNOLOGY TITLE: SCHEMATIC HIGH EFFICIENCY POLYPHASE , SYNCHRONOUS BUCK CONVERTER WITH VERY LOW DCR INDUCTOR SIZE N/A SCALE = NONE 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only DATE: IC NO. LTC3875EUJ / LTC3874EUFD DEMO CIRCUIT 2142A 03/05/14 13:03:42 SHEET 2 1 REV. 2 OF 3 A 5 4 3 OPTIONAL 5.5V BIAS U3 LTC3621EDCB-2 D5 +5.5V VIN C47 1.0uF 25V D 5 INTVCC 6 MODE 2 JP6 FB VIN ON EXTVCC +5.5V 1 744043003 R80 187k 1% C48 22pF 3 VOUT COUT27 OPT 1210 R76 COUT28 OPT 1210 COUT29 OPT 1210 COUT30 OPT 1210 COUT31 OPT 1210 COUT32 OPT 1210 COUT33 OPT 1210 COUT34 OPT 1210 COUT35 OPT 1210 COUT36 OPT 1210 OPT C38 22uF 10V 0805 D VOUT 7 R77 10K 1% RUN VOUT L5 3.3uH 4 1 R83 23.2K 1% 2 COUT37 OPT 1210 OFF COUT38 OPT 1210 COUT39 OPT 1210 COUT40 OPT 1210 COUT41 OPT 1210 COUT42 OPT 1210 COUT43 OPT 1210 COUT44 OPT 1210 COUT45 OPT 1210 COUT46 OPT 1210 3 BIAS 1 C37 10uF 16V 0805 SW GND CMDSH-3-TR 2 DYNAMIC LOAD CIRCUIT C C EXT PULSE E15 VOUT J7 SUD50N04-8M8P-4GE3 U4 LTC6992IS6-1 2 R90 3 154k MOD OUT GND V+ SET DIV R87 5 0 +5.5V R91 4 1M U5 LT1803IS5 C41 5 R88 20K 0.1uF 2 70Hz, 3% Duty Cycle R92 20K R85 2.2 JP7 PULSE 6 2 1 R93 681K 1% 3 C43 1.0uF V+ VOUT R89 4 EXT SUD50N04-8M8P-4GE3 R94 10K 1% J9 1 R95 301 1% R98 0.01 2512 R100 301 1% E16 GND CUSTOMER NOTICE INTVCC1 UD1 LTC6908S6-1#PBF R104 A OPT 1 C45 R102 237k 1% 0.1uF 2 3 V+ OUT1 GND OUT2 SET MOD 6 5 B 2 82.5 1% R97 0.01 2512 R99 5K IOUT STEP C44 1.0uF R96 B 2 Q20 3 INT C42 150pF -IN Q21 1 VOUT 1 V+IN 3.3 1% 1 R101 EXTCLK OPT 4 APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. MI VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. YINGTI Y. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. TECHNOLOGY TITLE: SCHEMATIC HIGH EFFICIENCY POLYPHASE , SYNCHRONOUS BUCK CONVERTER WITH VERY LOW DCR INDUCTOR SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 4 3 N/A SCALE = NONE 2 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only DATE: IC NO. LTC3875EUJ / LTC3874EUFD DEMO CIRCUIT 2142A 03/05/14 13:05:40 SHEET 3 1 REV. 2 OF 3 A