Octal transparent latch for high-speed bus isolation
The Texas Instruments SN74AC573N is an octal D-type transparent latch with tri-state outputs in a 20-pin DIP package. When the latch-enable (LE) input is high, data at the D inputs flows through to the Q outputs; when LE goes low, the last data state is latched. The output-enable (OE) bar puts all eight outputs into high-impedance state for bus isolation, letting multiple devices share a data bus without contention.
2.5ns propagation delay — what it buys on the bus
The 74FCT573APC is a functional peer with the same pinout and octal latch function, but its 8.5ns propagation delay is more than three times slower. For a drop-in upgrade that keeps the same 20-DIP footprint and tri-state bus architecture, the 74AC family is the faster, wider-temperature choice.
Active lifecycle — no near-term obsolescence
The SN74AC573N carries an Active product status, meaning TI continues to manufacture and support this part. This makes it suitable for both new designs and ongoing production BOMs without supply-risk planning for an LTB event. ROHS3 compliance is confirmed, so the part meets current EU and global restrictions on hazardous substances. No special handling or exemption paperwork is needed for European-market equipment.
Through-hole 20-DIP — board fit and handling
For prototyping or rework, the DIP package is socket-friendly — no hot-air or reflow station needed. In production, wave-solder or selective-solder processes handle the through-hole leads.