1 2 REVISION HISTORY ECO REV __ E7 DATE YING C. 11-9-11 C1 JP1 2.2uF 2 100V 1210 U1 ON R1 (OPT) 1% 0603 OFF E1 16 5 E11 TRACK/SS1 C3 1nF JP2 SYNC 2 12 RT 3 3 E6 SYNC E2 L1 22uH C5 0.22uF 0603 1 VOUT1 5V / 1A D1 DFLS160L 14 VIN1 VIN2 TRACK/SS2 EN/UVLO RT E9 VIN2 9 10 13 R2 200K 1% TRACK/SS1 SYNC BD BOOST1 BOOST2 SW1 SW2 C4 1nF C2 2.2uF 100V 1210 + 7V - 60V C14 22uF 100V OPT E10 GND 4 DA1 FB1 C7 (OPT) DA2 FB2 A E12 TRACK/SS2 6 C6 0.22uF 0603 7 L2 15uH E3 VOUT2 3.3V / 1A 8 11 D2 DFLS160L C8 22pF R5 34k C10 47uF 10V 1210 C12 1uF 10V 0603 17 C9 47uF 10V 1210 2 1 2 C11 1uF 10V 0603 15 1 R3 (OPT) 1% 0603 LT3988EMSE 1 GND EN/UVLO PRODUCTION 2 E8 C13 22uF 100V OPT GND + 1 7V - 60V A 2 APPROVED VIN1 3 VIN1 DESCRIPTION R4 57.6k E5 E4 GND B GND R7 10k R6 10.2K 1% NOTE: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE IN 0402. ALL CAPACITORS ARE IN 0402. B 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. 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. 2. INSTALL SHUNTS AS SHOWN. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 1 TECHNOLOGY HZ YING C. 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 TITLE: SCHEMATIC DUAL 60V STEP-DOWN REGULATOR SIZE IC NO. LT3988EMSE N/A DEMO CIRCUIT 1677A DATE: Tuesday, March 27, 2012 2 SHEET 1 REV. 2 OF 1