The ADM1487EARZ is a low power Data Transceiver with ±15kV ESD protection suitable for half-duplex communication on multipoint bus transmission lines. It is designed for balanced data transmission and complies with Telecommunication Industry Association/Electronics Industries Association (TIA/EIA) standards RS-485 and RS-422. The ADM1487E has a 1/4 unit load receiver input impedance that allows up to 128 transceivers on a bus. Because only one driver is enabled at any time, the output of a disabled or power-down driver is three-stated to avoid overloading the bus. The driver outputs are slew rate limited 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.