REVISION HISTORY DESCRIPTION APPROVED ECO REV 1 - PRODUCTION DATE K. SZOLUSHA May 24, 2013 C12 OUT (Opt) 1210 C13 * SEE DEMO MANUAL FOR INPUT RANGE E1 E15 36 R21 30 124k 1% 0603 C10 0.01µF R1 28.7k 1% 350kHz R2 5.1k C7 (Opt) 1210 C8 (Opt) 1210 E4 20 SW 21 SW 38 SW 8 SW SW 9 10 NC PWMOUT VMODE RT VC OUT C6 (Opt) 1210 INTVCC E7 RS1 R8 25 0.39 1% 1206 37.4k 1% 28 27 LEDR23 M1 Si2318CDS-T1-GE3 (Opt) 0603 23 R11 R10 0 Ohm 0805 34 3 LED+ 32V LED MAX 650mA E8 C17 (Opt) DIM/SS GNDK DIM PWM GND 35 C16 47nF 300Hz ISN GND 33 PWM VREF 4 (Opt) 0603 GND R14 (Opt) 0603 32 ISP U1 LT3954EUHE 24 R13 CTRL PGND E9 31 37 R20 (Opt) 0603 R6 165k 1% PGND INTVCC C5 4.7µF 50V 1210 R7 1.00M 1% 0603 EN/UVLO 17 SYNC FB 16 SYNC 2 R4 147k 1% 0603 SYNC PGND E6 E14 1 PGND SYNC 15 EN/UVLO R19 (Opt) 0603 PGND R3 499k 0603 14 E10 R5 1M Q1 (Opt) (Opt) 6 OUT R16 (Opt) 0603 R17 (Opt) R18 PVIN VIN E3 PGND R22 (Opt) C4 4.7µF 50V 1210 PGND C1 1µF 50V 1206 OUT OUT PDS560-13 R12 0 Ohm 1206 13 E2 VIN 5V - 30V* 22µH DR125-220 12 R15 (Opt) 1206 C3 10µF 50V 1210 C15 (Opt) 1210 E5 D1 C2 10µF 50V 1210 OUT CTRL (Opt) 1210 L1 PVIN PVIN 5V - 30V* C14 (Opt) 1210 (Opt) 0805 -VMODE R9 R24 100k 0603 0 Ohm 0603 INTVCC E11 VMODE SYNC E12 GND E13 C11 1µF 10V GND C9 4.7nF INTVCC E16 INTVCC CUSTOMER NOTICE NOTES: UNLESS OTHERWISE SPECIFIED. 1. RESISTORS ARE 0402 CASE SIZE. 2. CAPACITORS ARE 0603 CASE SIZE. 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. APPROVALS PCB DES. RB APP ENG. KEITH S. TITLE: SCHEMATIC SIZE C:\PADS PROJECTS\2079A(LT3954EUHE)\SCH\2079A_REV1.DSN THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. TECHNOLOGY N/A 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 40VIN LED CONVERTER WITH INTERNAL PWM GENERATOR IC NO. REV. LT3954EUHE DC2079A DATE: May 24, 2013 1 SHEET 1 OF 1