These devices can be used as two 8-bit transceivers or one 16-bit transceiver. They allow data transmission
from the A bus to the B bus or from the B bus to the A bus, depending on the logic level at the direction-control
(DIR) input. The output-enable (OE
) input can be used to disable the devices so that the buses are
effectively isolated.
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.
When V
?is between 0 and 1.5 V, the devices are in the high-impedance state during power up or power down.
CC
However, to ensure the high-impedance state above 1.5 V, OE
?should be tied to V? through a pullup resistor;
CC
the minimum value of the resistor is determined by the current-sinking capability of the driver.
?and power-up 3-state. The I? circuitry
These devices are fully specified for hot-insertion applications using I
off off
disables the outputs, preventing damaging current backflow through the devices when they are powered down.
The power-up 3-state circuitry places the outputs in the high-impedance state during power up and power down,
which prevents driver conflict.