SN74ABT245BN (TEXAS INSTRUMENTS)

The SN74ABT245BN is an octal Bus Transceiver with 3-state outputs. It is designed for asynchronous communication between data buses. The devices transmit data from the A bus to the B bus or from the B bus to the A bus, depending on the logic level at the direction-control (DIR) input. The OE input can be used to disable the device so the buses are effectively isolated. To ensure the high-impedance state during power up or power down, OE should be tied to VCC through a pull-up resistor, the minimum value of the resistor is determined by the current-sinking capability of the driver. This device is fully specified for hot-insertion applications using Ioff and power-up 3-state. The Ioff circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down. The power-up 3-state circuitry places the outputs in the high-impedance state during power up and power down, which prevents driver conflict.