The SN75ALS181 is a differential driver and receiver pair designed for bidirectional data communication on multipoint bus transmission lines. The design provides for balanced transmission lines and meets TIA/EIA-422-B and TIA/EIA-485-A, and CCITT recommendations V.10, V.11, X.26, and X.27. The SN75ALS181 combines a 3-state differential line driver and a differential-input line receiver that operate from a single 5-V power supply. The driver and receiver have active-high and active-low enables, respectively, that can be externally connected together to function as a direction control. The driver differential outputs and the receiver differential inputs are connected to separate pins for greater flexibility and 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 changes, making the device suitable for party-line applications. The SN75ALS181 is characterized for operation from 0C to 70C.