This dual-bit noninverting bus transceiver uses two separate configurable power-supply rails. The A port is designed to track V_CCA. V_CCA accepts any supply voltage from 1.2 V to 3.6 V. The B port is designed to track V_CCB. V_CCB accepts any supply voltage from 1.2 V to 3.6 V. This allows for universal low-voltage bidirectional translation between any of the 1.2-V, 1.5-V, 1.8-V, 2.5-V, and 3.3-V voltage nodes.

Description

The SN74AVC2T245 is designed for asynchronous communication between two data buses. The logic levels of the direction-control (DIR) input and the output-enable (OE) activate either the B-port outputs or the A-port outputs or place both output ports into the high-impedance mode . The device transmits data from the A bus to the B bus when the B-port outputs are activated and from the B bus to the A bus when the A-port outputs are activated. The input circuitry on both A and B ports always is active and must have a logic HIGH or LOW level applied to prevent excess I_CC and I_CCZ.

The SN74AVC2T245 is designed so that the control pins (DIR1, DIR2, and OE) are supplied by V_CCA.

This device is fully specified for partial-power-down applications using I_off. The I_off circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down.

The V_CC isolation feature ensures that if either V_CC input is at GND, both ports are in the high-impedance state.

To ensure the high-impedance state during power up or power down, OE must be connected to V_CC through a pull-up resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.