5 VCC LB R16 330 0603 RB1 RA2 GND E19 DZ1 8 E24 RXEN1 9 DXEN1 10 TE485_1 11 TE485_2 12 E35 VL E20 RA2 E21 RB2 R14 10k 0603 E41 DY2 DZ2 E40 VL 32 RB2 33 RA2 34 GND 35 VL 36 LB 37 GND APPROVED MITCHELL LEE Z1 DY2 DZ1 DZ2 RXEN1 RXEN2 DXEN1 DXEN2 TE485_2 B1 GND Y1 Z1 DY2 A2 E25 24 DZ2 B2 E26 23 RXEN2 22 DXEN2 VCC 20 VDD C2 2.2uF 25V TP4 E36 E31 E32 VCC C4 2.2uF 25V TP2 VDD FEN TP1 CAP CAP TP7 SW SW A1 4 25 TP3 C1 470nF 25V Z1 J5 E34 GND VDD VCC C3 2.2uF 25V A2 B2 GND C Y2 Z2 5 A2 4 B2 3 GND 2 H/F DZ2 D Y1 1 VEE E42 GND 2 21 VCC 485/232_2 DY2 B1 26 Z2 DY1 A1 5 27 GND TE485_1 E30 28 Y2 485/232_1 R15 10k 0603 RA1 38 RB1 Y1 VEE 7 E29 Z1 VCC 39 DY1 Y1 29 B2 SW E16 B1 GND 6 E28 30 A2 CAP 5 Z1 E39 GND 4 A1 19 RB2 Y1 E27 B1 3 31 VCC 18 CHANNEL 2 RA2 3 E23 C GND B1 VCC 17 E18 R13 10k 0603 2 FEN R12 10k 0603 A1 16 E17 1 VCC VL H/F GND VL E22 15 DZ1 LTC2872IUHF 485/232_2 DY1 RB2 U1 E13 A1 E33 RA1 13 CHANNEL 1 GND 05/23/11 R17 330 0603 E12 GND RB1 DATE PRODUCTION CHANNEL 1 C5 100nF 25V D1 GREEN J3 RA1 DESCRIPTION 1 Y2 1 VEE CHANNEL 2 E38 J2 GND REV D2 GREEN GND GND ECO VL J4 485/232_1 GND 1 VCC VCC 3V - 5.5V D 2 REVISION HISTORY J1 VL 1.7V -VCC VL 3 14 VCC 4 E37 Z2 J6 VL TP5 L1 22uH TP6 VL GND B B DXEN1 RXEN1 VL 1 2 EXT 3 GND 5 4 R1 100 JP2 VL JP1 VL RXEN1 6 VL VL 1 EXT 3 2 DXEN1 GND 5 6 4 R2 100 E1 RXEN1 VL 1 EXT 3 2 TE485_1 GND 5 6 R3 100 E2 DXEN1 485/232_1 TE485_1 JP3 VL 4 JP4 VL VL 1 EXT 3 2 485/232_1 GND 5 6 4 R4 100 E3 TE485_1 LB VL JP5 VL 1 EXT 3 2 GND 5 6 LB 4 R5 100 E4 485/232_1 FEN H/F 2 H/F GND 5 6 4 R6 100 VL VL 1 EXT 3 2 FEN GND 5 6 R7 100 E6 H/F E5 LB JP7 VL JP6 VL 1 EXT 3 485/232_2 E7 FEN 4 DXEN2 TE485_2 VL JP8 VL 1 EXT 3 2 485/232_2 GND 5 6 2 TE485_2 GND 5 6 4 R8 100 4 R9 100 E8 485/232_2 JP10 VL JP9 VL 1 EXT 3 RXEN2 VL VL 1 EXT 3 2 GND 5 6 DXEN2 4 R10 100 E9 TE485_2 JP11 VL 1 EXT 3 2 GND 5 6 RXEN2 4 R11 100 E10 DXEN2 E11 RXEN2 E15 GND CHANNEL 1 GND CHANNEL 2 E14 CUSTOMER NOTICE A REPRESENTS PROBE PADS. 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. USED TO MANUFACTURE PCB Y1 MH1 MH3 1 NOTES: UNLESS OTHERWISE SPECIFIED, 1. ALL RESISTORS AND CAPACITORS ARE 1206. Y2 1 TOOLING HOLES 1 MH2 1 1 MH4 1 4 TECHNOLOGY PCB DES. MI APP ENG. MITCHELL L. TITLE: SCHEMATIC SIZE 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 RS232/RS485 DUAL MULTIPROTOCOL TRANSCEIVER WITH INTEGRATED TERMINATION N/A REPRESENTS STAND OFFS THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 APPROVALS SCALE = NONE DATE: IC NO. LTC2872IUHF DEMO CIRCUIT 1851A Wednesday, November 02, 2011 1 SHEET 1 REV. 1 OF 1 A