5 4 3 2 1 * SEE DEMO MANUAL PVIN E1 PVIN 3.3V - 36V D * J1 BANANA JACK + C1 C2 10uF 50V 1210 C4 56uF,50V 50HVT56M SGND C24 10uF 50V 1210 C25 10uF 50V 1210 + C5 OPT 5 6 7 8 R1 R33 0 Q1 Q2 BSC035N04LS G 4 0 1 2 3 J2 BANANA JACK SGND E14 10 R25 143K (300kHz) C28 1nF R18 309K C29 1nF R19 309K PWM_OUT1 FAULT PWM_OUT2 PWM_OUT3 SS RT LED_ISP R29 0 B D5 1 J3 J4 J5 VEE C13 OPT E5 1 31 ISN SYNC FB 13 + 2 R30 0 LED_ISN 4 2 8 7 5 6 4 Q6 Si7234DP 2 8 7 5 6 LED+ LED+ LED+ 4 LED1- LED2- LED3- Q4 Q7 Si7234DP Si7234DP 21 J6 R12 0 R13 0 27 PWM1 25 PWM2 23 PWM3 D3-1 BAT54A J7 C J8 5 6 7 8 8 7 5 6 22 C17 OPT PWM3 28 R17 309K 14 ISP D2 OPT DI123 24 PWM2 VC3 R23 100K D4-1 BAT54A 1 4 PWM1 Q8 BSC010N04LS R14 4.02K PWM2 4 Q9 BSC010N04LS 17 PWM3 R27 1K 16 C19 1nF 4 Q10 BSC010N04LS 15 18 R22 100K PWM1 VC2 R21 100K VF NEG VC1 C18 10nF R20 100K 11 CTRL3 19 82.5K 2 CTRL2 VEE R16 R36 0 20 E7 4 32 CTRL1 VEE SYNC 3 5 6 7 8 9 C15 OPT 1 2 3 E13 + D4-2 BAT54A 3 2 5 6 7 8 8 BAT54A C10 OPT E3 C9 10uF 1206 C16 470uF 1 2 3 7 E12 2 C12 470uF 1 2 3 E11 PWM1 + 3 D3-2 C11 470uF 3 5 LED+ KRL6432 3 4 E10 744355182 3 2 VEE 1nF CTRL2 C27 1nF 29 BG E6 R5 0.003 CTRLT 37 C26 CTRL1 6 35 C OPT VEE R9 33 R7 100K VEE R10 100K 100K 30 Q3 Q5 BSC026N04LS VREF 26 R6 100K R8 C14 2.2uF L1 0.82uH C8 22uF 6.3V 0805 EN/UVLO SW 3 34 3 E4 INTVCC 1 2 1 EN/UVLO PWM3 VIN 0805 E8 C6 0.22uF 1 36 SGND TG E16 PWM2 0 D1 PMEG4002EB BOOST U1 LT3744EUHE 12 SGND CTRL3 R4 E9 C7 1uF 50V 1 R3 100K SGND E15 1 2 3 R2 OPT SGND 5 6 7 8 VIN E2 1 D R32 0.005 KRL6432 R31 0 C21 C22 C23 33nF 33nF 33nF B SBR1A40S3 NOTE: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE 0603. ALL CAPACITORS ARE 0603. A A 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. TECHNOLOGY TITLE: SCHEMATIC SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 4 3 2 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only N/A DATE: HIGH CURRENT SYNCHRONOUS INVERTING BUCK-BOOST LED DRIVER IC NO. LT3744EUHE DEMO CIRCUIT 1930A SHEET Thursday, August 27, 2015 1 1 OF REV. 3 1