The SNx4AHC125 devices are quadruple bus buffer
gates featuring independent line drivers with 3-state
outputs. Each output is disabled when the associated
output-enable ( OE) input is high. When OE is low, the
respective gate passes the data from the A input to its
Y output.
To ensure the high-impedance state during power up
or power down, OE must be tied to VCC through a
pullup resistor; the minimum value of the resistor is
determined by the current-sinking capability of the
driver.