MC74AC640 Overview
MC74AC640 MC74ACT640 Octal Bidirectional Transceiver with 3ĆState Outputs The MC74AC640/74ACT640 octal bus transceiver is designed for asynchronous two-way munication between data buses. The device transmits data from bus A to bus B when T/R = HIGH, or from bus B to bus A when T/R = LOW. The enable input can be used to disable the device so the buses are effectively isolated.