These dual 4-bit D-type latches feature 3-state outputs designed
specifically for bus driving. These devices are particularly suitable
for implementing buffer registers, I/O ports, bidirectional bus
drivers, and working registers.
The dual 4-bit latches are transparent D-type latches. While the
latch-enable (LE) input is high, the Q outputs follow the data (D)
inputs in true form, according to the function table. When LE is low,
the outputs are latched. When the clear () input goes low, the Q outputs go
low independently of LE. The outputs are in the high-impedance state
when the output-enable ()
input is at a high logic level.
The SN54ALS873B and SN54AS873A are characterized for operation
over the full military temperature range of -55°C to 125°C.
The SN74ALS873B and SN74AS873A are characterized for operation from
0°C to 70°C.