The ADM485E /ADM487E/ADM1487Eare 5 V low power data transceivers with ±15 kV ESD protection suitable for half duplex communication on multipoint bus transmission lines. They are designed for balanced data transmission and comply with TIA/EIA standards RS-485 and RS-422. The ADM487E and the ADM1487E have a 1/4 unit load receiver input impedance that allows up to 128 transceivers on a bus, while the ADM485E allow up to 32 transceivers on a bus. Since only one driver is enabled at any time, the output of a disabled or powerdown driver is three-stated to avoid overloading the bus.The driver outputs are slew rate-limited in order to reduce EMI and data errors caused by reflections from improperly terminated buses. Excessive power dissipation caused by bus contention or output shorting is prevented with a thermal shutdown circuit. The parts are fully specified over the industrial temperature ranges and are available in 8-lead SOIC packagesAPPLICATIONSEnergy/power meteringLighting systemsIndustrial controlTelecommunicationsSecurity systemsInstrumentation