4 INTVCC E1 1 2 20K E3 4 JP1 PHASMD 120 90 60 DEG DEG DEG 1 4 INTVCC PLLIN RUN1 2 C1 OPT 2 REV __ CLKOUT RUN1 ON 5 1 REVISION HISTORY ECO 4 1 SW1 RUN1 R2 OPT 2 3 RUN1 R1 VIN 3 MODE PS BM CCM 3 5 DESCRIPTION 2 APPROVED DATE JIAN L. 9-30-13 PRODUCTION E2 JP2 VIN R3 OPT E4 OFF VIN+ D 6 3 D J1 R29 OPT C21 0.1uF R30 OPT OPT TK/SS2 C19 220nF VOUT1 TRSET1 1 2 2 5 6 7 8 1 2 3 5 6 7 8 COUT3 100uF 6.3V 1210 COUT1 100uF 6.3V 1210 + COUT2 330uF 2.5V 7343 + COUT4 C10 10uF 10V 330uF 2.5V 7343 J3 VOUT1 1.0V / 30A J4 GND C INTVCC EXTVCC C13 1uF 0.25uH 744301025 DCR = 0.32m OHM VO1_SNS- R20 10 VIN C14 4.7uF E8 VO1_SNS- 10V 23 D2 R23 22 0 C18 21 20 CMDSH-3 CIN5 10uF 1210 E9 R24 10 Q3 BSC050NE2LS 4 0.1uF TG2 CIN4 10uF 1210 INTVCC L2 SW2 BG2 R28 INTVCC 4 100K VO2_SNS+ VO2_SNS+ VOUT2 VOUT2 Q4 BSC010NE2LSI COUT7 100uF 6.3V 1210 0.33uH 744301033 DCR = 0.32m OHM COUT8 100uF 6.3V 1210 COUT5 + 330uF 2.5V 7343 J5 VOUT2 COUT6 + 330uF 2.5V 7343 C20 10uF 10V 1.5V / 30A J6 GND R34 4.64k 1% VO2_SNS- R36 10 R35 931 1% E11 VO2_SNS- C22 1uF E13 GND VO1_SNS+ 1 2 3 VIN 2.2 25 Q2 BSC010NE2LSI 4 R18 5 6 7 8 32 31 CLKOUT 33 34 RUN1 PHASMD PGOOD INTVCC CMDSH-3 26 24 R16 10 VOUT1 5 6 7 8 TCOMP1 36 37 38 35 ILIM MODE/PLLIN 0 BG1 VIN- E7 VO1_SNS+ R32 100K 1% EXTVCC B TRSET1 TCOMP1 39 SNS1- R31 OPT EXTVCC E12 SW2 27 R17 D1 19 SGND/PGND TG2 28 GND E6 L1 0.1uF TG1 J2 R12 715 1% C7 30 29 CIN2 10uF 1210 R11 3.57k 1% 4.5V - 14V + 1 2 3 TRK/SS2 BOOST2 SNS2- R27 R26 0 BG2 SNSA2+ ENTMPB 41 TK/SS2 18 E10 C17 OPT 10 C16 220nF VOSNS2- ENTMPB VO2_SNS- R22 OPT EXTVCC IFAST R25 20k 9 INTVCC VOSNS2+ RUN2 VO2_SNS+ C15 OPT ITH2 17 8 TK/SS2 R21 30.1k BOOST1 VIN 16 7 TG1 BG1 IFAST 6 VFB2 1% SW1 CIN1 270uF 16V + Q1 BSC050NE2LS 4 SW1 ITH1 FREQ 5 U1 LTC3875EUJ VOSNS1- CIN3 10uF 1210 CLKOUT 15 ITH2 VOSNS1+ ILIM TRSET2 R19 10K C ITH2 4 14 C12 1.5nF ITH1 VIN INTVCC 3.01K R10 1K TRSET2 3 C11 150pF TAVG C9 220pF 13 2 TK/SS1 TAVG C8 1.5nF 1 TK/SS1 SNSD1+ ITH1 TCOMP2 C6 OPT 220nF 12 R14 20k 220nF VFB1 TCOMP2 C5 OPT R9 R7 OPT C4 SNSA1+ VO1_SNS- R13 13.3k CIN12 270uF 16V 1 2 3 R8 OPT C3 VO1_SNS+ R15 10.7K 1% R5 OPT SNSD2+ C2 0.1uF 11 0 R6 OPT 40 TRK/SS1 TK/SS1 R4 1 VIN VIN E5 E15 RUN2 B E14 PGOOD PGOOD JP3 ENTMPB 1 OFF 2 TRSET1 3 ON R37 10k R33 TRSET2 R40 10k TG1 RUN2 ON C26 OPT 5 OFF TCOMP1 C25 OPT R45 OPT TG2 SW2 R39 OPT BG1 SET R33=60K ohm FOR FAST TRANSIENT RESPONSE @ VOUT2 TG2 SW2 BG2 CUSTOMER NOTICE C24 OPT R42 OPT RN2 OPT SW1 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. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. 1 RN4 OPT 1 R41 OPT 1 RN1 OPT 2 C23 OPT 2 2 2 BG1 BG2 2 R38 OPT 1 VIN TCOMP2 A RN3 OPT SW1 R44 OPT 4 1 SW2 RUN2 R43 5k 6 3 TAVG OPT TG1 TITLE: SCHEMATIC HIGH EFFICIENCY, DUAL-OUTPUT 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 TECHNOLOGY HZ JIAN L. 4 3 2 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. REV. LTC3875EUJ 2 DEMO CIRCUIT 2000A Monday, October 07, 2013 SHEET 1 1 OF 2 A 5 4 3 2 1 OPTIONAL JUMPERS FOR SINGLE OUTPUT/DUAL PHASE OPERATION R48 VO2_SNS- OPT R51 TK/SS2 OPT R54 RUN1 OPTIONAL 5.5V BIAS VIN RUN2 OPT 1 ITH2 OPT 2 C27 10uF 16V JP5 FOR DUAL PHASE OPERATION, REMOVE R24, R36, R21, R25, AND SHORT VOUT1 AND VOUT2. BIAS VIN R52 10K TG2 8 4 3 2 1 LOAD STEP CIRCUIT 1 Q6 FDMS3620S OPT 1 + 8 COUT9 330uF 7343 + COUT10 330uF 7343 C29 100uF 6.3V 1210 9 7 6 5 5 6 7 9 9 7 6 5 BG2 J8 1 SW2 OPTIONAL 3mm x 3mm Dual-MOSFETs VIN COUT11 COUT12 C33 + 100uF 330uF OPT 6.3V 7343 7343 1210 TG2 4 7 BG1 BG2 R56 0.005 2512 9 J10 IOUT2 2 1 C34 OPT 6.3V 1210 1 C36 0.22uF 3 4 7 GND J9 VOUT2 B C35 0.22uF RJK0305DPB Q8 5 4 3 2 3 IO1STEP CLK E17 R55 10K E18 4 R57 10K 3 2 1 2 1 E16 1 + C VOUT1 4 C32 0.22uF CIN9 OPT 8 9 8 CIN8 OPT TG1 C31 0.22uF VOUT2 VIN Q10 FDPC8011S, OPT C30 OPT 6.3V 1210 RJK0305DPB Q7 5 4 3 2 SW1 J7 1 VOUT1 2 3 4 5 1 5 6 2 IOUT1 Q9 FDPC8011S, OPT C28 10uF 16V 2 3 4 5 Q12 FDMS3620S OPT 8 B 4 SHDN ADJ D OPT R50 34.8K 1% CIN7 OPT 2 3 4 4 3 2 CIN11 OPT BG1 7 GND EXTVCC R47 5 TG1 8 9 IN +5.5V VIN CIN6 OPT Q5 FDMS3620S OPT 2 3 4 CIN10 OPT 1 LT1761ES5-SD 5 OUT 1 OPTIONAL 5mm x 6mm Dual-MOSFETs C 3 R49 10K ON OFF Q11 FDMS3620S OPT U2 VIN 3 2 1 ITH1 R53 TK/SS1 5 VO1_SNSD VFB2 OPT 3 R46 VFB1 IO2STEP CLK E19 GND R58 0.005 2512 10 6 5 10 6 5 LOAD STEP CIRCUIT 2 CUSTOMER NOTICE SW1 SW2 LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL 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 APPROVALS PCB DES. APP ENG. TECHNOLOGY HZ JIAN L. 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, DUAL-OUTPUT SYNCHRONOUS BUCK SIZE N/A SCALE = NONE 2 DATE: IC NO. REV. LTC3875EUJ 2 DEMO CIRCUIT 2000A Monday, October 07, 2013 SHEET 2 1 OF 2 A