5 4 3 2 1 E10 REVISION HISTORY VCC VCC ECO REV DESCRIPTION APPROVED DATE MITCHELL L. 03/30/11 J1 VCC 3V - 5.5V E16 RO D2 GREEN RO VL J4 C5 100nF 25V R15 330 0603 LB E12 GND GND 330 0603 E36 U1 LTC2871IUHF 4 R12 R13 R14 RX485 5 10k 0603 10k 0603 10k 0603 DX485 6 E19 7 E20 8 DIN1 DIN2 C E21 9 E22 GND DX232 10 RX232 11 E23 12 VEE VCC GND 32 34 VL RO 35 36 LB H/F A CH2 B RX485 VCC DX485 Y DI GND DIN1 Z DIN2 DOUT1 DX232 DOUT2 RX232 VCC VEE VDD FEN GND ROUT2 E25 31 E26 30 E27 29 E28 28 E29 26 Y E30 24 E31 23 E32 22 VCC C2 1uF 25V 39 19 18 17 16 15 14 13 C4 2.2uF 25V E38 TP2 VDD VDD E37 CAP LB JP1 EXT GND H/F JP2 VL 1 2 3 4 5 6 VL LB EXT GND VL 1 2 3 4 5 6 VL H/F EXT GND CH2 JP4 VL 1 2 3 4 5 6 VL TE485 EXT GND 1 2 3 4 5 6 RX485 JP5 VL VL CH2 EXT GND 1 2 3 4 5 6 VL RX485 EXT GND R4 R5 R6 100 100 100 100 100 100 H/F E3 E4 TE485 CH2 DX485 JP6 VL R3 LB GND 2 Y 1 VL R2 E2 B Z J5 TP6 R1 E1 A 4 GND TE485 JP3 B VEE TP5 SW SW VL VCC 5 3 VEE VL L1 10uH TP7 VL TP3 C3 1uF 25V C TP4 20 VDD C1 220nF 25V DOUT1 VCC VEE CAP Z DOUT2 21 GND TP1 A 25 FEN E35 RIN2 VCC E24 GND RIN1 B 27 VEE CH2 RIN2 VEE 3 VL ROUT1 SW VL RIN1 GND RS232 RS485 VL VEE VEE 2 ROUT2 TE485 1 VEE E18 GND RS232 E17 ROUT1 37 E13 GND 33 GND 38 GND CAP J3 D E34 TE485 R11 J2 GND DI E33 H/F GND RS232 D1 GREEN RS232 VL 1.7V -VCC E11 VL D PRODUCTION RS485 RS485 2 VCC 1 2 3 4 5 6 VL DX485 EXT GND B RX232 JP8 VL 1 2 3 4 5 6 VL DX232 EXT GND 1 2 3 4 5 6 FEN JP9 VL VL RX232 EXT GND R7 R8 R9 100 100 100 1 2 3 4 5 6 FEN E15 E6 E7 E8 DX485 DX232 RX232 E5 RX485 DX232 JP7 VL E9 GND FEN E14 GND A REPRESENTS PROBE PADS. USED TO MANUFACTURE PCB Y1 MH1 1 NOTES: UNLESS OTHERWISE SPECIFIED, 1. ALL RESISTORS AND CAPACITOR ARE 1206. 1 Y2 MH2 1 1 MH3 1 MH4 1 CUSTOMER NOTICE CONTRACT NO. 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. APPROVALS TOOLING HOLES REPRESENTS STAND OFFS THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 4 3 2 TECHNOLOGY PCB DES. MI ENG. MITCHELL L. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only TITLE: SCHEMATIC RS232/RS485 MULTIPROTOCOL TRANSCEIVER WITH INTEGRATED TERMINATION SIZE B DATE: IC NO. REV LTC2871IUHF DEMO CIRCUIT 1786A Wednesday, March 30, 2011 2 SHEET 1 1 OF 1 A