SN54F573,SN74F573,pdf

These 8-bit latches feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.

The eight latches of the ´F573 are transparent D-type latches. While the latch enable (LE) input is high, the Q outputs follow the data (D) inputs. When the latch enable is taken low, the Q outputs are latched at the logic levels set up at the D inputs.

A buffered output enable  input can be used to place the eight outputs in either a normal logic state (high or low logic levels) or a high- impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly.