This dual-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 1.65 V to 5.5 V. The B port is designed to track
VCCB. VCCB accepts any supply voltage from 1.65 V to
5.5 V. This allows for universal low-voltage bidirectional translation between any of the 1.8-V,
2.5-V, 3.3-V, and 5-V voltage nodes.
The SN74LVC2T45 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 on both A and B ports always is active and must have a logic HIGH or LOW level applied to
prevent excess ICC and ICCZ.
The SN74LVC2T45 is designed so that the DIR input circuit is supplied by
VCCA. This device is fully specified for partial-power-down applications
using Ioff. The Ioff circuitry disables the outputs,
preventing damaging current backflow through the device when it is powered down.
The VCC isolation feature ensures that if either
VCC input is at GND, both ports are in the high-impedance state. NanoFree™
package technology is a major breakthrough in IC packaging concepts, using the die as the