The SNx4HC573A devices are octal transparent D-type latches that 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.
While the latch-enable (LE) input is high, the Q outputs respond to the data (D) inputs. When LE is low, the outputs are latched to retain the data that was set up.