The "HC573 devices are octal transparent D-type latches designed for 2-V to 6-V VCC operation.
●When the latch-enable (LE) input is high, the Q outputs follow the data (D) inputs. When LE is low, the Q outputs are latched at the logic levels of the 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) 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 increased drive provide the capability to drive bus lines without interface or pullup components.
●OE\ does not affect the internal operations of the latches. 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.
● 2-V to 6-V VCC Operation
● Wide Operating Temperature Range of 55°C to 125°C
● 3-State Outputs Directly Drive Bus Lines
● Balanced Propagation Delays and Transition Times
● Bus Driver Outputs Drive Up To 15 LS-TTL Loads
● Significant Power Reduction Compared to LS-TTL Logic ICs