5 4 3 2 1 REVISION HISTORY ECO REV DESCRIPTION DATE 2 PRODUCTION 5/11/11 VIN E1 22uF,50V SANYO 50CE22LX D7 VOUT2 CMDSH-4E PGOOD2 C24 1uF 10V 0603 E8 GND C3 47uF 10V 1206 3 R4 12.4k 12 C14 OPT R8 10k R6 20k C5 D4 B340A 680pF 10 BOOST2 U1 LT3507AEFE SW1 SW1 SW2 FB1 FB2 VC1 VC2 E10 TRK/SS1 TRK/SS2 E3 14 E4 15 E5 32 NIC., NPIM74C100MTRF L3 10uH VOUT3 VOUT3 E12 5V @ 1.8A C26 1uF 10V 0603 E14 D9 VOUT3 CMDSH-4E C10 47uF 10V 1206 GND 37 C9 0.22uF 38 0603 BOOST3 BIAS SW3 TRK/SS4 DRIVE 24 R11 20k C11 680pF R12 10.2k D6 B240A C19 47pF 23 FB3 FB4 VC3 VINSW 22 E16 TRK/SS3 UVLO TRK/SS3 OVLO 26 28 C6 C15 VISHAY TAIYO YUDEN FB MJ3216HS800 IHLP-4040DZ-01 L4 FB1 22UH BEAD VIN C21 0.01UF 0603 C22 2.2UF,50V 1210 + E9 C 21 31 29 1 R23 10k 30 R13 1.07k 9 8 R14 49.9k R15 100k R17 18.2k R18 3.32k VOUT4 Q1 ZXTCM322 7 RT/SYNC GND VOUT2 3.3V @ 1.5A E11 TRK/SS2 C29 OPT E13 VOUT4 2.5V @ 0.3A C27 1uF 10V E15 0603 GND C28 OPT C12 2.2uF 0603 R16 499 E17 B TRK/SS4 C20 0.1uF E19 SYNC R19 107k (450kHz) VIN C23 22UF,50V SANYO 50CE22LX CUSTOMER NOTICE A NOTES: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE IN 0402. ALL CAPACITORS ARE 0402. 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 C25 1uF 10V 0603 C16 OPT 25 R20 OPT OPTIONAL CIRCUIT PGOOD3 GND R9 10k 16 GND 39 27 RUN3 NC R22 100k E18 SD RUN2 20 18 19 B 47pF PGOOD2 VOUT2 C4 22uF,6.3V 1206 680pF R7 20k D5 B240A PGOOD1 E7 R5 31.6k RUN1 NC 17 34 C13 0.1uF VIN D8 CMDSH-4E NIC., NPIM74C8R2MTRF L2 8.2uH C7 0.1uF R10 53.6k C18 OPT C2 0.22uF 25V 0603 33 TRK/SS1 C8 0.1uF R3 100k 13 C17 47pF 11 C PGOOD3 R2 100k 3 E6 2 BOOST1 R1 100k 2 VOUT1 1.8V @ 2.7A C1 0.47uF 0603 NIC., NPIM74C4R7MTRF L1 4.7uH VOUT1 1 PGOOD1 4 D D3 CMDSH-4E OPT VIN3 VIN2 D2 CMDSH-4E OPT VIN1 D1 CMDSH-4E OPT 36 VOUT2 D 35 GND EDWIN L. R21 OPT 0603 + CIN4 VIN2 CIN3 2.2uF 50V 1210 6 E2 CIN2 2.2uF 50V 1210 VIN1 CIN1 2.2uF 50V 1210 5 VIN 7V - 36V APPROVED 4 3 APPROVALS PCB DES. HZ APP ENG. EDWIN L. TECHNOLOGY 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 TRIPLE MONOLITHIC STEP-DOWN REGULATOR WITH LDO SIZE N/A SCALE = NONE 2 IC NO. LT3507AEFE REV. 2 DEMO CIRCUIT 1781A DATE: Monday, August 01, 2011 SHEET 1 1 OF 1 A