5 4 3 2 1 D D VIN U1 E1 LTC7138EMSE L1 150uH VIN R1 2M C1 22uF + 200V GND VIN SW RUN ANODE 3 R2 OPT 2 E4 3 14 1 VFB RUN JP3 C ON SS OFF 12 R3 0 5 16 10 7 GND C3 OPT GND R4 OPT VPRG2 GND C R7 OPT [3] 4. SMALLER AMOUNT OF COUT CAN BE USED FOR APPLICATIONS THAT CAN TOLERATE HIGHER OUPUT RIPPLE. REFER TO THE DATA SHEET FOR APPLICATIONS INFORMATION. B 2 A JP1 6 3 17 OPT ISET 8 VIN NC NC NC NC FB0 VOUT C9 1.8V / 3.3V / 5V 0.1uF 400mA E3 1 11 VOUT C8 C10 OPT 1210 9 R8 E5 R6 0 D1 SBR1U200P1 3 VPRG1 C6 C7 100uF 10V 1210 CDRH105R C4 47nF FBO E2 1 OVLO 2 4 13 15 4V - 140V C2 1uF 200V 2220 [3] B 2 A 1 B B JP2 NOTE: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE 0603. ALL CAPACITORS ARE 0603. 2. FOR 5V OUTPUT, VIN RANGE IS 6V-140V. [3] A VOUT JP1 JP2 1.8V B B 3.3V A B 5.0V B A EXT. R A A CUSTOMER NOTICE 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 APPLICATION. COMPONENT SUBSTITUTION AND PRINTED APP ENG. CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. TECHNOLOGY TITLE: SCHEMATIC 5 4 3 IC NO. LTC7138EMSE DEMO CIRCUIT 2172A N/A SCALE = NONE A HIGH EFFICIENCY, HIGH VIN, 400mA STEP-DOWN REGULATOR SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only DATE: Tuesday, January 06, 2015 2 SHEET 1 1 REV. 2 OF 1