5 D VEMI+ E2 6V ‐ 24V Transients to 42V 4 VEMI C39 0.1µF 50V 0402 E4 3 FB1 330 Ohm MPZ2012S331AT000 L5 0.22µH IHLP‐1212BZ‐ER‐R22M11 VISHAY C29 10µF 50V X5R 1206 C30 10µF 50V X5R 1206 TP1 + GND CPVIN2 10µF 50V X7R 1210 C6 22µF 50V D INTVCC 28 C1 4.7uF 10V X5R 0603 VIN TP2 CPVIN1 4.7µF 50V X7R 1206 CVIN 1µF 50V X7R 0805 C36 0.1µF 50V 0402 23 37 14 C37 0.1µF 50V 0402 INTVCC BST1 VIN SW1 ON EN/UVLO 1 2 1% 3 OFF VIN FB2 C 22 VOUT1 R6 19.1k 1% E9 VOUT2 R7 19.1k 1% SW2 SW2 PVIN3 CPVIN3 4.7µF 10V X7R 0805 R10 100k 1% JP1 17 3 EN/UVLO SW3 R8 19.1k 1% E11 PG2 FB3 PG1 1 PG2 11 PG3 12 L1 3.3µH XAL5030‐332MEC Coilcraft R1 806k 1% C3 4.7pF R2 5 6 7 L2 1.5µH XFL5015‐152MEC Coilcraft * C4 47µF 10V X5R 1206 200k 1% C11 0.1µF 10V 0402 E1 VOUT1 5V / C5 0.IµF 50V E3 0603 GND VOUT1 26 EXT PVIN3 VOUT2 R3 464k 1% VOUT2 JP6 C15 47µF 10V X5R 1206 C14 12pF C35 47µF 10V X5R 1206 R5 25 L3 15 1.0µH NPIS42LS1R0YTRF NIC Comp. Corp. VOUT3 PG1 C2 0.1µF 10V 0402 PVIN2 FB1 PVIN3 4 PVIN1 BST2 R4 340k 1 U1 LT8601EUJ#PBF VEMI‐ VIN 2 * 200k 1% VOUT3 R11 187k 1% E5 VOUT2 3.3V / C16 0.IµF 50V E6 0603 GND E7 C18 47µF 10V X5R 1206 C17 22pF C VOUT3 1.8V / * C19 0.IµF 50V E8 0603 GND R12 24 150k 1% PG1 PG2 PG3 E12 32 ON B 1 18 3 29 JP4 E21 R18 28.7k 1% C33 TRKSS2 TRKSS2 1 47nF X7R 19 36 SYNC INTVCC SYNC 1 PULSE SKIP 2 BIAS TRKSS1 TRKSS2 RUN3 CPOR 3 BURST 31 JP7 C27 220pF R15 100k 1% RT N/C N/C POREN 2 8 9 13 ON 21 20 47nF X7R 2 OFF 10 E16 33 B E18 39 POREN R19 100k 1% 38 40 41 TRKSS1 SYNC GND GND GND GND GND (Opt) C32 E20 TRKSS1 RST 16 27 30 34 35 C31 VOUT2 GND GND GND GND E15 GND GND GND PG3 RST 2 3 OFF NOTE: UNLESS OTHERWISE SPECIFIED. JP5 E17 1. All Resistors 0603. 2. All Capacitors 0603. See Demo Manual for details on VOUT current capability. R21 RUN3 RUN3 EXT * 100k 1% 1 2 3 RUN A CUSTOMER NOTICE PG2 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. JP2 TECHNOLOGY 5 4 3 A LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY TITLE: SCHEMATIC 42V Triple Monolithic Synchronous 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 www.linear.com Phone: (408)432-1900 Fax: (408)434-0507 N/A SCALE = NONE 2 IC NO. LT8601EUJ DEMO CIRCUIT 2346A MODIFY DATE: Mar 01, 2016 2346A_REV2 1 SHEET REV. 2 1 OF 1