5 4 3 2 1 REVISION HISTORY ECO REV 1 1 DESCRIPTION APPROVED DATE REBUILD WITH CHANGES WALKER B. 4-6-10 D D SHDN/UVLO 27 28 C3 1uF 6.3V 25 24 VREF NC 26 2 NC VOUT 1 SW 20 18 VOUT LT3599EFE LED4 VIN LED3 AGND LED2 VREF LED1 R17 232K VIN 5 R3 100K 4 E17 9 R8 31.6K SHDN/UVLO R16 37.4K E18 1 SS 8 R9 53.6K (1MHz) R10 16.5K (80mA) C4 47nF SYNC PWM SHORTLED ON 2 OFF OPTIONAL COMPONENTS R11 10K FB1 (OPT) VEMI E15 C10 100pF L2 1206 C6 (OPT) 0603 R15 64.9K B OPENLED JP1 DISABLE4 R14 200K CTRL R4 100K 11 15 ISET DISABLE4 23 GND 13 PWM R7 976K VO_SW 29 PVIN C12 4.7uF 50V E9 LED1- 6 VREF 21 R6 80.6K SHORTLED SYNC 3 16 PVIN E8 LED2- E7 LED3- 7 CTRL 19 CTRL E12 TSET RT 17 14 CTRL E6 LED4- C2 4.7uF 50V C R5 52.3K 22 E16 OPENLED FB GND LED2+ LED1+ E5 E4 U1 SHDN/UVLO C9 (OPT) C LED4+ LED3+ E3 E2 3 3.1V - 5.5V VIN E11 1 VC VIN NC 10 E10 NC GND 12 C1 3.3uF 25V 2 NC PVIN E1 * PVIN 8V - 16V D1 L1 10uH LPS4018-331 PVIN (OPT) C5 + 10uF 50V (OPT) C7 (OPT) 1210 C8 2.2nF E13 B E14 R1 100K R13 100K * See Quick Start Guide 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. A CONTRACT NO. APPROVALS PCB DES. ENG. WALKER B. 4 3 TITLE: SCHEMATIC 4-CHANNEL 120mA LED DRIVER WITH +/-15% CURRENT MATCHING SIZE N/A THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 TECHNOLOGY H.Z. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only DATE: 2 IC NO. REV LT3599EFE 1 DEMO CIRCUIT 1327B Tuesday, April 13, 2010 SHEET 1 1 OF 1 A