These 8-bit flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. The devices are particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.
The eight flip-flops of the AC574 devices are D-type edge-triggered flip-flops. On the positive transition of the clock (CLK) input, the Q outputs are set to the logic levels set up at the data (D) inputs.
A buffered output-enable (OE)\ input can be used to place the eight outputs in either a normal logic state (high or low logic levels) or the high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and the increased drive provide the capability to drive bus lines in a bus-organized system without need for interface or pullup components.
OE\ does not affect 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 pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
|VCC (Min) (V)|
|VCC (Max) (V)|
|Voltage (Nom) (V)|
|F @ Nom Voltage (Max) (Mhz)|
|ICC @ Nom Voltage (Max) (mA)|
|tpd @ Nom Voltage (Max) (ns)|
|IOL (Max) (mA)|
|IOH (Max) (mA)|
|Operating Temperature Range (C)|
|Military||SN54AC574||QML certified for Military and Defense Applications|