5 4 3 2 1 * SEE DEMO MANUAL FOR IOUT MAX. VS. ‐VIN E1 J1 PGND R11 C1 10µF 50V 1210 C2 10µF 50V 1210 C3 10µF 50V 1210 C22 C4 10µF 50V 1210 4 ‐4.5V TO ‐38V L1A 3.5µH 74485540350 Wurth Electronik L1A‐1 E2 1 R8 (Opt) C23 L1B‐3 (Opt) D1 PMEG6030EP MP1‐D MP1 SUD19P06‐60‐E3 R19 0 Ohm 2512 L1B 3 2 3.5µH 74485540350 Wurth Electronik (Opt) L1B‐3 ISN (Opt) 13 GND INTVEE 16 R14 17 100k BG ISN ISP 7 6 R20 0 Ohm BIAS 8 9 MP1‐S BIAS INTVEE C15 2.2uF 16V 0805 C16 2.2µF 100V 1210 U1 LT8709EFE MODE PG FBY 4 (Opt) VC E9 PG PG ‐VIN 5 C17 0.1µF E11 ‐VIN ‐4.5V TO ‐38V CUSTOMER NOTICE 3 E10 IMON C7 4.7nF THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 4 SYNC EN/FBIN INTVCC APPROVALS C:\PROJECTS\1-A-PROJECTS\1-PROJECTS-CURRENT\DC2148A-3 RUDY\1-SCH\DC2148A-3.DSN 5 (Opt) R6 10k 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. 1. ALL RESISTORS 5%, 0603. 2. ALL CAPACITORS 0603. PG IMON R5 88.7k 1% 400kHz NOTE: UNLESS OTHERWISE SPECIFIED. B 130k 1% C20 21 20 C14 0.22µF A ‐VIN IMON RT C10 2.2uF 16V 0805 INTVCC 18 R16 0 Ohm 12 2 C8 47pF SS INTVCC BIAS R7 1 SYNC 3 19 SYNC ‐VIN R23 100k R15 E5 CSP INTVCC R45 (Opt) EN/FBIN INTVCC B TG GND R3 13.3k 1% 10.0k 1% EN/FBIN 11 14 CSN C9 10 INTVEE R4 E6 C ISP R18 ISN CSP 2.2µF 100V 1210 MODE MP1‐D R17 ISP BG ‐VIN SYNC L1A‐1 TG R10 (Opt) E3 E4 * TG (Opt) EN/FBIN C26 8mm Dia. SMD (Opt) VOUT J4 VOUT ‐12V + E8 (Opt) (Opt) C24 C19 (Opt) 1210 R12 22uF 16V 1210 C25 C C13 22uF 16V 1210 R13 22uF 16V 1210 C6 0.002 1% 2W R9 2512 (Opt) C12 22uF 16V 1210 (Opt) MP1‐S (Opt) 1210 C5 MN1 FDMS86520L R1 ‐VIN ‐4.5V TO ‐38V (Opt) 1210 C28 C11 22uF 16V 1210 (Opt) R2 0.006 1% 1W 2512 BG C18 10µF 50V 1210 + CSP C21 220µF 50V 10mm Dia. SMD J2 ‐VIN D J3 GND PGND 15 D E7 SCALE = NONE 2 TECHNOLOGY TITLE: SCHEMATIC SIZE N/A IC NO. 1630 McCarthy Blvd. Milpitas, CA 95035 www.linear.com Phone: (408)432-1900 Fax: (408)434-0507 A LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY Negative Input Synchronous Multi‐Topology DC/DC Controller LT8709EFE REV. DC2148A MODIFY DATE: Friday, February 06, 2015 3 SHEET 1 1 OF 2 CSP C35 L1A‐1 MP1‐D R24 MP1‐D TG (Opt) 1210 C27 (Opt) 2512 L1B‐3 ISP ISN C36 C29 (Opt) 1210 VOUT L1A‐1 C37 (Opt) 1210 ‐VIN R36 MN2 (Opt) PowerPAK SO8 (Opt) 1210 R39 (Opt) (Opt) 1210 INTVEE ISP BG MP1‐S BIAS BG ISN R25 (Opt) CSP R34 (Opt) E12 (Opt) 2512 EN/FBIN SYNC INTVEE ‐VIN R26 (Opt) C33 R30 1k (Opt) BIAS (Opt) 0805 INTVCC TG ISN ISP R31 (Opt) R32 (Opt) R42 20k (Opt) C34 (Opt) 0805 D5 (Opt) SOD‐323 R33 (Opt) L1B‐3 (Opt) 2512 R21 INTVEE (Opt) 3 C39 BIAS R22 INTVCC D4 ISN ISP R37 (Opt) R38 (Opt) VOUT Q1 FMMT593 (Opt) SOT23 PG OPTIONAL LEVEL SHIFTING CIRCUITRY EN/FBIN R44 20k (Opt) (Opt) PowerDi5 ‐VIN ISN TECHNOLOGY PCB DES. C30 APP ENG. TITLE: SCHEMATIC (Opt) C31 (Opt) ‐VIN 2 ISP D2 BAT46WJ (Opt) SOD323 R41 100k (Opt) R40 1k (Opt) APPROVALS R28 SYNC R43 20k (Opt) (Opt) (Opt) 0805 (Opt) 2512 1 R35 1k (Opt) V_EXT E13 PGND Q2 MMBT2222A (Opt) SOT‐23 D3 BAT46WJ (Opt) SOD323 MP2 (Opt) PowerPAK SO8 R29 ‐VIN C38 0.1uF 100V (Opt) 1206 VOUT R27 MP1‐S PG L1A‐1 (Opt) 2512 C32 (Opt) SIZE N/A ‐VIN SCALE = NONE IC NO. 1630 McCarthy Blvd. Milpitas, CA 95035 www.linear.com Phone: (408)432-1900 Fax: (408)434-0507 LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY Negative Input Synchronous Multi-Topology DC/DC Controller LT8709EFE REV. DC2148A MODIFY DATE: Tuesday, January 13, 2015 3 SHEET 2 OF 2