1 2 3 4 5 6 7 8 REVISION HISTORY ECO 3 2 4 1 JP3 4 CIN7 4.7uF 50V 1210 R33 C43 TRK/SS1 6 ITH1 7 20K 1% 20K 1% 9 VFB2 330pF VOUT1 10 ITH2 C44 R34 12 S2+ OPT R36 11 TRK/SS2 R35 3.3nF E10 8 VFB1 C15 0.22uF 11.8K 1% 0 13 TRK/SS2 14 R37 C47 R69 S2- OPT 15 OPT 0.1uF C49 VIN R43 40.2K 1% 22pF 16 17 R38 RUN2 19 1 2 CLKOUT SENSE1- SW1 TRK/SS1 TG1 ITH1 BOOST1 VFB1 PGND1 VFB2 BG1 ITH2 VIN TK/SS2 INTVCC SENSE2+ EXTVCC SENSE2- BG2 DIFFP PGND2 DIFFN BOOST2 DIFFOUT TG2 RUN2 SW2 ILIM1 JP2 C48 R41 OPT OPT PGOOD2 ILIM2 PGOOD1 36 R40 OPT 1% E11 R57 8.45K 1% L1 VO1+ RS1 C20 L1- 0.1uF 33 TG1 32 R9 Q6 OPT 0.9uH D1 0 31 DFLS1100-7 30 VOUT1 0 2010 COUT3 100uF 1210 R58 0 4 + COUT2 330uF 4V 7343 VOUT1 2.5V / 15A + COUT1 330uF 4V 7343 J4 GND Q2 RJK0330DPB BG1 VO1- VIN VIN 2.2 28 INTVCC EXTVCC 26 C11 4.7uF 10V BG2 C17 0.1uF 50V CIN8 4.7uF 50V 1210 Q3 RJK0305DPB 25 NOTES: UNLESS OTHERWISE SPECIFIED, CIN11 OPT 1210 1. ONLY APPLY LOAD FROM J3 TO J4 FOR VOUT1 2. ONLY APPLY LOAD FROM J5 TO J6 FOR VOUT2 24 R25 23 D2 R59 INTVCC 0 22 4 DFLS1100-7 C21 0.1uF 21 4 3.09K 3. ALL CAPCITORS AND RESISTORS ARE IN 0603. 4. INSTALL SHUNTS AS SHOWN. Q7 OPT R60 11.0K 1% 1% L2 TG2 20 RS2 SW2 J5 L2- 4 R70 0.9uH 4 VOUT2 0 2010 COUT6 100uF 1210 R62 0 Q8 OPT COUT5 + 330uF 4V 7343 + VOUT2 1.8V / 15A COUT4 330uF 4V 7343 J6 Q4 RJK0330DPB GND C OPT E3 R64 10 R65 10 OPT E14 VOUT2 VO2_SNSVO2_SNS+ C50 E2 B E12 R18 29 27 4 INTVCC 0 R73 J3 34 VOUT1 EXTVCC 2 2 S1+ 3.09K SW1 R39 OPT R12 OPT R56 35 1 2 3 3 R72 EXTVCC SENSE1+ RUN2 EXTVCC C 18 0 PHSASMD 39 ON OFF R11 OPT GND S1- R32 J2 4 S2+ 5 220pF B 4.5V to 26V + CIN1 220uF 50V S2- C42 R31 20K 1% MODE/PLLIN RUN1 4 5 6 7 8 4 ITEMP1 37 Q5 OPT 1 2 3 0.1uF FREQ 5 6 7 8 OPT 3 1nF ITEMP2 CLKOUT 1 2 3 C2 C41 A VIN VIN- 1 2 3 2 R2 J1 CIN9 OPT 1210 5 6 7 8 TRK/SS1 Q1 RJK0305DPB 38 1 2 3 1 0.22uF 5 6 7 8 LTC3855EFE 5 6 7 8 C14 5 6 7 8 OPT CIN6 4.7uF 50V 1210 R7 0 U1 1 2 3 S1+ S1- 1 2 3 R28 R3 0 VIN+ CIN3 4.7uF 50V 1210 E6 5 6 7 8 C38 JP1 CIN4 4.7uF 50V 1210 VIN Fsw = 250kHz (typ) R30 OPT RUN1 3 OPT E9 R29 OPT 1 2 3 22pF 5 6 7 8 OPT 1 2 R27 63.4K 1% SGND C37 ITEMP2 ON OFF CIN5 4.7uF 50V 1210 0 ITEMP1 RUN1 CIN10 OPT 1210 + CIN2 OPT R26 06/20/11 E5 JP4 1 VIN DATE MIKE S. VIN PLLIN R10 APPROVED PRODUCTION E15 E1 A DESCRIPTION 2 1 1 20.0K PHASMD 120 90 60 DEG DEG DEG INTVCC 3 R68 MODE PS BM FCM 2 INTVCC REV CLKOUT 1uF INTVCC GND INTVCC R42 OPT R46 100K 1% E4 R61 ILIM1 INTVCC R44 0 R66 100K 1% OPT ILIM2 E13 INTVCC R63 0 PGOOD1 PGOOD1 PGOOD2 PGOOD2 E16 TEMPERATURE COMPENSATION NETWORK FOR DCR SENSING ITEMP1 R45 OPTIONAL JUMPERS FOR SINGLE OUTPUT/DUAL PHASE OPERATION VFB1 R50 OPT VFB2 ILIM1 OPT TRK/SS1 R52 RUN2 R71 RN1 TRK/SS2 ITEMP1 C52 OPT OPT RN3 RN2 R47 ILIM2 OPT R67 C51 2 OPT R55 100K OPT ITEMP2 45.3K 1% 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. R53 OPT 100K 1 RUN1 2 ITH2 1 R49 CUSTOMER NOTICE 18.2K 1% 2 ITH1 R51 18.2K 1% 1 D ITEMP2 45.3K 1% APPROVALS PCB DES. APP ENG. MIKE S. SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 2 3 TITLE: SCHEMATIC DUAL OUTPUT SYNCHRONOUS BUCK CONVERTER OPT 1 TECHNOLOGY MI 4 5 6 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only IC NO. N/A SCALE = NONE LTC3855EFE REV. DEMO CIRCUIT 1617A-A DATE: Monday, June 20, 2011 7 SHEET 1 8 2 OF 1 D 1 2 3 4 5 6 7 8 REVISION HISTORY ECO 3 2 4 1 JP3 4 E5 JP4 CIN7 4.7uF 50V 1210 R33 C43 TRK/SS1 6 ITH1 7 20K 1% 20K 1% 9 VFB2 47pF VOUT1 10 ITH2 C44 R34 12 S2+ OPT R36 11 TRK/SS2 R35 1.5nF E10 8 VFB1 15K 0 C15 1nF 1% 13 TRK/SS2 14 R37 C47 R69 S2- 0 15 OPT 0.1uF C49 VIN R43 147K 1% OPT 16 17 R38 RUN2 19 1 2 SENSE1- SW1 TRK/SS1 TG1 ITH1 BOOST1 VFB1 PGND1 VFB2 BG1 ITH2 VIN TK/SS2 INTVCC SENSE2+ EXTVCC SENSE2- BG2 DIFFP PGND2 DIFFN BOOST2 DIFFOUT TG2 RUN2 SW2 ILIM1 JP2 C48 R41 OPT OPT PGOOD2 ILIM2 PGOOD1 R40 10 VO1+ L1 RS1 C20 L1- 0.1uF 33 TG1 32 R9 Q6 OPT 13uH D1 0 31 DFLS1100-7 30 VOUT1 0.008 2010 COUT3 10uF 1210 R58 OPT 4 + COUT2 OPT VOUT1 12V / 6A + COUT1 68uF 16V 7343 J4 GND Q2 BSC093N04LS BG1 VO1- VIN VIN 2.2 28 INTVCC EXTVCC 26 C11 4.7uF 10V BG2 C17 0.1uF 50V CIN8 4.7uF 50V 1210 Q3 BSC093N04LS 25 CIN11 OPT 1210 NOTES: UNLESS OTHERWISE SPECIFIED, 1. ONLY APPLY LOAD FROM J3 TO J4 FOR VOUT1 2. ONLY APPLY LOAD FROM J5 TO J6 FOR VOUT2 24 R25 23 D2 R59 INTVCC 0 22 4 DFLS1100-7 C21 0.1uF 21 4 OPT 3. ALL CAPCITORS AND RESISTORS VALUES ARE 0603. Q7 OPT 4. INSTALL SHUNTS AS SHOWN. R60 OPT L2 TG2 20 RS2 SW2 J5 L2- 4 R70 3.7uH 4 VOUT2 0.005 2010 COUT6 10uF 1210 R62 OPT Q8 OPT COUT5 + OPT + VOUT2 5V / 10A COUT4 220uF 6.3V 7343 J6 Q4 BSC093N04LS GND C OPT E3 R64 10 R65 10 0 E14 VOUT2 VO2_SNSVO2_SNS+ C50 E2 B E12 R18 29 27 4 INTVCC OPT R73 J3 34 VOUT1 EXTVCC 2 2 S1+ E11 R57 OPT SW1 R39 10 R12 0 OPT 35 1 2 3 3 R72 EXTVCC CLKOUT RUN2 EXTVCC C 18 OPT SENSE1+ 36 39 ON OFF R11 OPT PHSASMD R56 S1- R32 GND 4 S2+ 5 47pF B J2 S2- C42 R31 15K 1% MODE/PLLIN RUN1 4 5 6 7 8 4 ITEMP1 37 Q5 OPT 1 2 3 0.1uF FREQ 5 6 7 8 OPT 3 3.3nF ITEMP2 CLKOUT 1 2 3 C2 C41 13V to 36V + CIN1 220uF 50V VIN- 1 2 3 2 R2 A VIN CIN9 OPT 1210 5 6 7 8 TRK/SS1 Q1 BSC093N04LS 38 1 2 3 1 1nF 5 6 7 8 LTC3855EFE 5 6 7 8 C14 5 6 7 8 OPT CIN6 4.7uF 50V 1210 R7 0 U1 1 2 3 S1+ S1- 1 2 3 R28 R3 0 J1 E6 5 6 7 8 JP1 VIN+ CIN3 4.7uF 50V 1210 VIN Fsw = 250kHz (typ) R30 10 RUN1 C38 OPT E9 R29 10 1 2 3 OPT 5 6 7 8 OPT R27 383K 1% SGND C37 1 2 3 CIN4 4.7uF 50V 1210 + CIN2 OPT R26 ITEMP2 ON OFF CIN5 4.7uF 50V 1210 0 ITEMP1 RUN1 CIN10 OPT 1210 1 VIN 06/20/11 VIN PLLIN R10 DATE MIKE S. E15 E1 A APPROVED PRODUCTION 1 1 20.0K 3 R68 MODE PS BM FCM DESCRIPTION 2 CLKOUT PHASMD 120 90 60 DEG DEG DEG INTVCC 2 INTVCC REV 1uF INTVCC GND INTVCC R42 0 R46 100K 1% E4 R61 ILIM1 INTVCC R44 OPT R66 100K 1% 0 E13 ILIM2 INTVCC R63 OPT PGOOD1 PGOOD1 PGOOD2 PGOOD2 E16 TEMPERATURE COMPENSATION NETWORK FOR DCR SENSING ITEMP1 R45 OPTIONAL JUMPERS FOR SINGLE OUTPUT/DUAL PHASE OPERATION VFB1 R50 OPT VFB2 ILIM1 OPT TRK/SS1 R52 RUN2 R71 RN1 TRK/SS2 ITEMP1 C52 OPT OPT RN3 RN2 R47 ILIM2 OPT R67 C51 2 OPT R55 100K OPT ITEMP2 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. R53 OPT OPT OPT 100K 1 RUN1 2 ITH2 1 R49 CUSTOMER NOTICE OPT 2 ITH1 R51 OPT 1 D ITEMP2 APPROVALS PCB DES. APP ENG. MIKE S. SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 2 3 TITLE: SCHEMATIC DUAL OUTPUT SYNCHRONOUS BUCK CONVERTER OPT 1 TECHNOLOGY MI 4 5 6 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only IC NO. N/A SCALE = NONE LTC3855EFE REV. DEMO CIRCUIT 1617A-B DATE: Monday, June 20, 2011 7 SHEET 1 8 2 OF 1 D