REVISION # This circuit is proprietary to Linear Technology and supplied for use with Linear Technology parts. Customer Notice: Linear Technology has made a best effort to design a circuit that meets customer-supplied specifications; however, it remains the customers 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 Applications Engineering for assistance. REVISION HISTORY SD PC AD FD R13 R14 (Opt) 0805 0 0 0 0 1 1 DESCRIPTION DATE APPROVED 1st Release (-A) Change R20, C13, D2 to Opt. C7 to 0.1uF. 07/02/09 Kz PWMDRAIN (Opt) 1206 E2 M3 (Opt) LED BUCK / BUCK-BOOST C9 E14 E1 PVIN 8V - 40V (Opt) L1 22uH HC9-220-R OUT D1 1 Cooper Bussmann E3 R1 499k 1% GND C10 4.7uF 50V R2 0 Ohm PDS560-13 VIN 4.5V - 40V C4 1uF 50V E6 U1 SHDN / UVLO C11 2.2uF 100V * 1 E10 3 7 INTVCC R18 (Opt) * VIN GATE GND E15 GND SENSE SHDN/UVLO FB VREF ISP 12 14 E8 13 CTRL PWMOUT * * INTVCC C5 4.7uF 10V PWM SS VC GND RT 4 15 17 5 R3 11 R19 0 Ohm 0805 2 INTVCC R11 R17 22k R20 (Opt) E12 GND (Opt) C7 0.1uF C6 2200pF LED BOOST M2 Si2308DS-T1-E3 VISHAY 0 Ohm D2 (Opt) PWM E13 R9 22.1k 1% 9 ISN R7 140k 1% R10 R6 1M 1% PWMDRAIN CTRL R16 (Opt) 10 R5 (Opt) 16 E11 8 LED + 1A 0.10 1% C12 (Opt) RS1 6 R15 1M C8 (Opt) C3 2.2uF 100V 0.015 R4 90.9k 1% * C2 2.2uF 100V M1 Si7850DP-T1-E3 VISHAY E5 E7 RS2 3 2 C1 4.7uF 50V R8 28.7k 1% 400kHz PWM E9 PWM (Opt) C13 (Opt) APPROVALS * ASSY U1(IC) U1-3 (Name) E11 (Name) R10 -A LT3755EUD-2 OPENLED OPENLED 100k -B LT3755EUD-1 SYNC OPT SYNC DRAWN: Rudy Bautista ENGINEER: Keith Szolusha LINEAR TECHNOLOGY CORPORATION 1630 McCARTHY BLVD MILPITAS, CA. 95035 (408)432-1900 (408)434-0507 (FAX) Title: LT3755EUD-1/-2 APPROVED: CHECKED: Date: Tuesday, July 07, 2009 SD Document Number www.linear.com LTC Confidential For Customer Use Only High Voltage LED Controller Rev Demo Circuit 1268B C:\ORCADWIN\CAPTURE\1268B\1268B_REV1.DSN Sheet 1 1 of 1