74HC373 : Transparent Latch Type-D, 8 bits, 3 states, DIP20

74HC373 : D-Type Transparent Latch 8 bits

This 8-bit latches feature 3-state outputs suitable for implementing:

• buffer registers,
• I/O ports,
• bidirectional bus drivers,
• working registers.

The eight latches of the 74HC373 devices are transparent D-type latches (who stores the Data value 1/0 at the LE signal).
IF the latch-enable (LE) input is high THEN the Q outputs follow the data (D) inputs. 
IF the latch-enable (LE) is taken low THEN the Q outputs are latched at the levels that were set up at the D inputs (it stores the Data).

The 8-bit latches features a 3-states outputs capable to drives highly capacitive or relatively low-impedance loads.
The 74HC373 are particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.

The eight latches of the 74HC373 are all driven by the latch-enable (LE) signal at the same time.
The D data inputs are stored/latched on the Q outputs when the LE is taken low (the LE falling edge store the data).

IF output-enable (/OE) input is placed low THEN the outputs states (high or low) is made available on the Q output.
IF output-enable (/OE) input is high THEN the Q outputs are set to HIGH IMPEDANCE and isolates 74HC373 from the Data bus.
In the high-impedance state, the outputs neither load nor drive the bus lines significantly.
OE does not affect the internal operations of the latches. Old data can be retained or new data can be loaded while the outputs are keeps off (High Impedance).

Thanks to the high-impedance state and logic buffers on Qs output, the 74HC373 can drives data bus lines without additionnal interface or pullup components.

Technical details

• 74HC373 datasheet (pdf)