5 Description (continued)

Active bus-hold circuitry holds unused or undriven data inputs at a valid logic state. Use of pullup or pulldown resistors with the bus-hold circuitry is not recommended. The bus-hold circuitry on the powered-up side always stays active.

This device is fully specified for partial-power-down applications using I_off. The I_off circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down.

The V_CC isolation feature ensures that if either V_CC input is at GND, then 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 V_CC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.