ISO485 Datasheet | Burr-Brown

FEATURES q RS-485 AND RS-422 PATIBLE q 100% TESTED FOR HIGH-VOLTAGE BREAKDOWN q q q q RATED 1500Vrms SINGLE-WIDE 24-PIN PLASTIC DIP EASY TO USE LOW POWER: 180m W typ at 5Mbit/s DESCRIPTION The ISO485 differential, isolated bus transceiver uses Burr-Brown’s capacitively coupled isolation technology to provide high-speed, low cost bus isolation. The ISO485 is designed for bi-directional data munication on multipoint bus transmission lines and meets EIA Standard RS-485 as well as EIA Standard RS-422A requirements. The ISO485 uses high voltage 0.4p F capacitors instead of the LED and photodetector which are used in equivalent optocoupler solutions. As a consequence the part count of the isolated RS-485 channel is reduced from multiple optocoupler channels, an RS485 transceiver chip and supporting circuitry to one ISO485. The capacitors in the ISO485 provide a high voltage barrier, 1500Vrms and greatly reduce current spikes on the power line. The ISO485 bines a 3-state differential line driver and a differential-input line receiver both of which operate from a single 5V power supply. The driver differential outputs and the receiver differential input/ output bus ports are designed to offer minimum loading to the bus whenever the driver is disabled or VS = 0V. 3 VSA 15 VSB APPLICATIONS q MULTIPOINT DATA TRANSMISSION ON LONG BUS LINES IN NOISY ENVIRONMENTS RE A B 12 13 TRUTH TABLE RS-485 DE RE BUS 0 23 DE 11 22 GND A GND B 14 0 1 0 1 RX HIGH Z HIGH Z TX 0 1 1 International Airport Industrial Park - Mailing Address: PO Box 11400 Tel: (520) 746-1111 - Twx: 910-952-1111 - Cable: BBRCORP - ©1994 Burr-Brown Corporation - Tucson, AZ 85734 - Street Address: 6730 S. Tucson Blvd. - Tucson, AZ 85706 Telex: 066-6491 - FAX: (520) 889-1510 - Immediate Product Info: (800) 548-6132 PDS-1280C Printed in U.S.A. May, 1995 SPECIFICATIONS At TA = +25°C, VS = 5V, unless otherwise specified. ISO485P PARAMETER DRIVER DC CHARACTERISTICS Input Voltage High MIN Low MAX...