5 4 3 2 1 REVISION HISTORY ECO REV __ VIN VIN 6V - 55V DESCRIPTION 1 APPROVED DATE WALKER B. 2ND PROTOTYPE 01-26-11 EN/UVLO E4 + D C9 4.7uF 63V C7 2.2uF 100V 1210 GND VREF C10 2.2uF 100V 1210 R13 R12 100K 100K E5 E16 R7 270K 0603 R9 91K EN/UVLO D 1 2 R11 100K 3 ON OFF PWM1 E6 R18 100K R17 100K SW1 DA1 FB1 VOUT1 CTRL1 E9 LED1+ 9 51 50 VIN VIN BST1 U1 LT3597EUHG 33 CTRL1 30 NC R14 100K L1 100uH C1 EN/UVLO 26 PWM1 PWM3 VREF 29 E8 PWM2 28 E7 PWM3 JP1 C4 0.22uF 0603 PWM2 LED1 2 2 50V 1 4.7uF 1206 4 D1 DFLS160 6 R4 3.01K 7 R1 93.1K E1 LED1+ 19 20 LED1E12 C 32 CTRL2 CTRL2 E10 BST2 SW2 31 CTRL3 CTRL3 E11 DA2 FB2 27 SYNC SYNC E18 LED2 17 R20 10K BST3 SW3 ISET2 DA3 16 ISET3 FB3 44 CTRLM VOUT3 VREF LED3 22 21 2 39 D2 DFLS160 D4 C8 4.7uF 25V 0805 TP E19 OPT BIAS E17 C2 50V 1 R5 3.01K 41 4.7uF 1206 R2 93.1K 43 LED2E13 23 24 C6 0.22uF 0603 L3 100uH C3 1 50V D3 DFLS160 R6 3.01K 4.7uF 1206 R3 93.1K LED3E14 CUSTOMER NOTICE NOTE: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE 0402 4 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. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 LED3+ E3 t FAULT A B LED3+ R10 100K E15 LED2+ E2 35 2 R15 8.87K R21 100K 0603 LED2+ 34 R16 82.5K R19 49.9K L2 100uH 13 VREF TSET 12 25 BIAS FAULT GND 11 53 GND R25 20K 37 R24 20K 18 B ISET1 15 R23 20K C5 0.22uF 0603 46 RT 14 R22 33.2K VOUT2 C 48 3 TECHNOLOGY AK WALKER B. 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 STEP-DOWN LED DRIVER SIZE IC NO. REV. LT3597EUHG 2 DEMO CIRCUIT 1497A SCALE = NONE DATE: 2 Wednesday, February 02, 2011 SHEET 1 1 OF 1 A