Dual 4-Bit D-type Latches With 3-State Outputs

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.