The SN74AXCH2T45 is a two-bit non-inverting bus transceiver that uses two individually
configurable power-supply rails. The device is operational with both VCCA
and VCCB supplies as low as 0.65 V. The A port is designed to track
VCCA, which accepts any supply voltage from 0.65 V to 3.6 V. The B port is
designed to track VCCB, which also accepts any supply voltage from 0.65 V to
3.6 V. Additionally the SN74AXCH2T45 is compatible with a single-supply system.The SN74AXCH2T45 device is designed for asynchronous communication between data buses.
The device transmits data from the A bus to the B bus or from the B bus to the A bus, depending on
the logic level of the direction-control input (DIR). The SN74AXCH2T45 device is designed so the
control pin (DIR) is referenced to VCCA.Active bus-hold circuitry holds unused or undriven inputs at a valid logic state. Use of
pullup or pulldown resistors with the bus-hold circuitry is not recommended. If a supply is present
for VCCA or VCCB, the bus-hold circuitry always remains active on the A or B inputs respectively,
independent of the state of the direction control pin.This device is fully specified for partial-power-down applications using the
Ioff current. The Ioff protection circuitry ensures
that no excessive current is drawn from or to an input, output, or combined I/O that is biased to a
specific voltage while the device is powered down.The VCC isolation feature ensures that if either
VCCA or VCCB is less than 100 mV, both I/O ports
enter a high-impedance state by disabling their outputs.Glitch-free power supply sequencing allows either supply rail to be powered on or off in
any order while providing robust power sequencing performance.
