DESCRIPTION
On the positive transition of the clock (CLK) input, the Q output is set to the logic level set up at the data (D) input. A buffered output-enable ( OE ) input can be used to place the output in either a normal logic state (high or low logic levels) or the high-impedance state. In the high-impedance state, the output neither loads nor drives the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus lines without interface or pull-up components. OE does not affect the internal operations of the flip-flop. Old data can be retained or new data can be entered while 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 VCC through a pull-up resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. 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.
Unisonic Technologies
