The SN65176B and SN75176B devices combine a 3-state differential line driver and a differential input line receiver, both of which operate from a single 5- V power supply. The driver and receiver have activehigh and active-low enables, respectively, that can be connected together externally to function as a direction control. The driver differential outputs and the receiver differential inputs are connected internally to form differential input/output (I/O) bus ports that are designed to offer minimum loading to the bus when the driver is disabled or VCC = 0. These ports feature wide positive and negative common-mode voltage ranges, making the device suitable for partyline applications