5 R1 51k C2 10uF,6.3V 0805 E6 3 C3 0.22uF 16V L1 6.2uH SUMIDA CDRH5D28 C 2 C6 1000pF D3 B240A R4 20k 2 C19 OPT C8 1500pF CFF OPT 16 1 15 14 13 5 4 BOOST2 BOOST1 SW1 SW2 FB1 FB2 TRACK/SS2 TRACK/SS1 VC1 VC2 PG1 PG2 D2 1N4448W 1 2 7 6 9 8 10 C7 1000pF 11 R5 43k RT/SYNC R2 52.3k 1% 700kHz R9 100k PG1 E8 A C9 330pF GND C R6 56.2k R10 100k E9 R7 11.5k 1% PG2 E10 GND CUSTOMER NOTICE CONTRACT NO. 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. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 SUMIDA CDRH6D28 R8 10.7k 1% NOTES: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE IN OHMS, 0402. ALL CAPACITORS ARE 0402. C5 10uF,10V 1206 E7 OUT2 [email protected] D4 B240A C20 OPT R3 35.7k B E5 C4 0.22uF L2 16V 10uH 1 OUT1 [email protected] E22 TRACK/SS2 2 D1 1N4448W 2 1 U1 LT3508EFE VIN2 E21 E4 GND D E3 VIN1 TRACK/SS1 1 C1 10uF,50V 1210 GND SHDN E2 17 GND 2 E1 SHDN 12 D 3 1 VIN 6V - 36V 4 4 3 APPROVALS DRAWN: CHECKED: APPROVED: ENGINEER: KEITH S. DESIGNER: TECHNOLOGY KIM T. B 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only TITLE: SCHEMATIC A DUAL MONOLITHIC 1.4A STEP-DOWN SWITCHING REGULATOR SIZE DWG NO. A DC1060A-1 * LT3508EFE Monday, January 15, 2007 DATE: 2 SHEET 1 REV A-1 1 OF 2 5 C10 4.7uF,25V 1206 R12 51k C14 1000pF 23 22 R15 9.1k R14 12.4k 1% C17 1200pF R18 10k 1% FB1 FB2 TRACK/SS2 TRACK/SS1 VC1 VC2 PG1 PG2 11 C13 0.1uF 16V 18 17 1 VIN2 9 SW2 12 19 C15 1000pF 20 RT/SYNC R13 16.9k 1% 1.6MHz 2 D8 DFLS130 24 SW1 D7 1N4448W 1 2 C18 680pF L4 4.7uH E16 OUT2 3.3V@1A SUMIDA CDRH4D18C C C16 10uF,6.3V 0805 E17 GND D9 DFLS130 R16 11k GND GND GND GND E15 2 1 C11 22uF,6.3V 0805 SUMIDA CDRH3D18 1 GND GND L3 3.0uH E14 8 C12 0.1uF 16V BOOST2 BOOST1 E18 TRACK/SS2 U2 LT3508EUF 13 14 15 16 1 7 VIN1 D6 1N4448W 10 E23 2 C OUT1 1.8V@1A D E13 2 TRACK/SS1 E12 25 SHDN 1 E11 SHDN 21 GND 2 GND GND GND GND * 3 3 4 5 6 D VIN 5V - 16V 4 R17 35.7k 1% R19 11.5k 1% R21 100k E19 PG2 B B E20 GND * SEE QUICK-START GUIDE CUSTOMER NOTICE CONTRACT NO. 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 DRAWN: TECHNOLOGY KIM T. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only CHECKED: TITLE: SCHEMATIC APPROVED: DUAL MONOLITHIC 1A QFN STEP-DOWN SWITCHING REGULATOR ENGINEER: KEITH S. DESIGNER: SIZE DWG NO. A A DC1060A-1 * LT3508EUF Monday, January 15, 2007 DATE: 2 SHEET 1 REV A-1 2 OF 2