Part Category: Logic ICs

Manufacturer: Texas Instruments High-Performance Analog

Description: Bus Transceiver, LVC/LCX/Z Series, 1-…

The SN74LVC8T245 is an eight bit non-inverting bus
transceiver with configurable dual power supply rails
that enables bidirectional voltage level translation.
The SN74LVC8T245 is optimized to operate with
VCCA and VCCB set at 1.65 V to 5.5 V. 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 5.5-V voltage nodes.
The SN74LVC8T245 is designed for asynchronous
communication between two data buses. The logic
levels of the direction-control (DIR) input and the
output-enable (OE) input 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 is always active
and must have a logic HIGH or LOW level applied to
prevent excess ICC and ICCZ.
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, all outputs are in the high-impedance state.
To ensure the high-impedance state during power up
or power down, OE should be tied to VCC through
a pullup resistor; the minimum value of the resistor
is determined by the current-sinking capability of the
driver.
The SN74LVC8T245 is designed so that the control
pins (DIR and OE) are supplied by VCCA.