SINGLE-BIT DUAL-SUPPLY BUS TRANSCEIVER WITH CONFIGURABLE VOLTAGE TRANSLATION

DESCRIPTION

This single-bit noninverting bus transceiver uses two separate

configurable power supply rails. The A port is designed to track

VCCA. VCCA accepts any supply voltage from 1.65V to 5.5V. The B

port is designed to track VCCB. VCCB accepts any supply voltage

from 1.65V to 5.5V. This allows for universal low-voltage

bidirectional translation between any of the 1.8V, 2.5V, 3.3V and

5V voltage nodes.

The U74LVC1T45 is designed for asynchronous

communication between two data buses. The logic levels of the

direction-control (DIR) input activate either the B port outputs or the

A port outputs. 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

is always active on both A and B ports and must have a logic HIGH

or LOW level applied to prevent excess ICC and ICCZ.

FEATURES

* Fully Configurable Dual-Rail Design Allows Each Port to Operate

Over the Full 1.65V to 5.5V Power-Supply Range

* VCC Isolation Feature – If Either VCC Input Is at GND, Both Ports

Are in the High-Impedance State

* DIR Input Circuit Referenced to VCCA

* ±24mA Output Drive at 3.3V

* IOFF Supports Partial-Power-Down Mode Operation