5 4 3 2 1 REVISION HISTORY ECO REV 2 DESCRIPTION APPROVED DATE PRODUCTION CHARLIE Z. 09-21-09 D D R5 10 D3 36V VIN C1 10uF 35V +6V C2 10uF 35V C3 + 10uF 35V C7 (OPT) D4 B0540W R7 10K 1 SENSE+ TP6 R10 2 SENSE- R22 C13 47pF R12 113K 1% C16 (OPT) 4 RUN C19 1000pF 1 OFF 3 7 R17 ON 2 6 C20 (OPT) 8 (OPT) JP2A BURST C21 1000pF +6V JP2B 10 11 DCM 4 23 EXTVCC 12 CCM +6V 13 16 D5 1N5819HW Q1A Si4942DY C9 22uF 16V C5 22uF 16V C6 22uF + 16V C8 (OPT) TP3 VOUT 12V@2A max TP5 GND SGND PGND RUN BG1 FCB BG2 PLLFLTR SW2 PLLIN TG2 EXTVCC +6V C15 1uF 21 L1 C18 4.7uF 10uH C C14 0.1uF IHLP4040DZ-01 19 Q2A Si4942DY 2 20 18 Q1B Si4942DY D6 B0540W 4 17 STBYMD R23 NC NC NC NC NC NC NC NC 15 14 R26 0 C22 0.22uF 16V 25 28 29 D7 B0540W SENSE+ R25 1 C24 1nF SENSE- 32 R19 0.025 2% +6V 33 R20 12.4K 1% 22 VOSENSE BOOST2 9 JP2C R8 10 VOUT ITH INTVCC 5 (OPT) JP1 RUN 26 SENSE- R13 8.06K 1% C12 3.3nF 4.7V Q2B Si4942DY 3 D1 VIN 24 7 8 R15 51K SENSE+ VOS+ C4 0.22uF 16V 1 VOS+ R11 30K SW1 0 5 6 VIN BOOST1 R24 2 3 C U1 LTC3780EUH TG1 C11 68pF 100 1% SS SGND SGND 100 1% PGOOD TP8 3 31 R9 GND 1 TP4 27 7 8 30 5 6 EXTVCC C10 0.22uF VIN 6V - 32V TP1 +6V PGOOD TP2 47.5K 1% B B SYNC TP10 RUN R21 (OPT) C23 0.01uF A CUSTOMER NOTICE 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. CONTRACT NO. APPROVALS PCB DES. HELEN ENG. CHARLIE TECHNOLOGY TITLE: SCHEMATIC HIGH EFFICIENCY BUCK-BOOST DC/DC CONVERTER SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 4 3 2 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only A DATE: IC NO. REV LTC3780EUH 2 DEMO CIRCUIT 1155A Tuesday, November 24, 2009 SHEET 1 1 OF 1 A