SCLS242L October 1995 – September 2014 SN54AHC573 , SN74AHC573
PRODUCTION DATA.
Refer to the PDF data sheet for device specific package drawings
The SNx4AHC573 devices are octal transparent D-type latches designed for 2-V to 5.5-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 pull-up 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 pull-up resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
INPUTS | OUTPUT Q |
||
---|---|---|---|
OE | LE | D | |
L | H | H | H |
L | H | L | L |
L | L | X | Q0 |
H | X | X | Z |