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
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.