The HD74ALVC162834 is an 18-bit universal bus driver designed for 2.3 V to 3.6 V VCC operation. Data flow from A to Y is controlled by the output enable (OE). The device operates in the transparent mode when the latch enable (LE) is low. When LE is low, the A data is latched if the clock (CLK) input is held at a high or low logic level. If the LE is high, the A data is stored in the latch/flip flop on the low to high transition of CLK. When OE is high, the 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 registor; the minimum value of the registor is determined by the current sinking capability of the driver.