The ADM3491-1 is a low power, differential line transceiver designed to operate using a single 3.3 V power supply. Low power consumption, coupled with a shutdown mode, makes it ideal for power-sensitive applications. It is suitable for communication on multipoint bus transmission lines. The ADM3491-1 is intended for balanced data transmission and complies with both Electronic Industries Association (EIA) Standards RS-485 and RS-422. It contains a differential line driver and a differential line receiver, making it suitable for full-duplex data transfer. The input impedance is 19 kΩ, allowing up to 50 transceivers to be connected on the bus. A thermal shutdown circuit prevents excessive power dissipation caused by bus contention or by output shorting. This feature forces the driver output into a high impedance state if a significant temperature increase is detected in the internal driver circuitry during fault conditions. If the inputs are unconnected (floating), the receiver contains a fail-safe feature that results in a logic high output state. The ADM3491-1 is fabricated on BiCMOS, an advanced mixed technology process combining low power CMOS with fast switching bipolar technology. APPLICATIONS Telecommunications DTE–DCE interface Packet switching Local area networks Data concentration Data multiplexers Integrated services digital network (ISDN) AppleTalk Industrial controls