8-bit addressable latch for 5 V bus systems
The CD74HCT259MT: It takes a single data input and routes it to one of eight outputs selected by the address lines — a 1:8 demultiplexing latch. This is different from a transparent latch (like the 74FCT573) where all eight bits are written simultaneously with a single enable. The addressable architecture is useful for sequentially updating registers, scanning LED banks, or distributing control signals across multiple peripherals without needing a separate decoder.
16 ns propagation delay — timing budget for 5 V logic
The 16 ns propagation delay from address or data input to output is the headline timing spec.
The supply range matches the 5 V ±10% rail common in legacy telecom, industrial control, and automotive body electronics. HCT inputs are TTL-compatible, so this latch can interface directly with 5 V CMOS or TTL logic without level translation. If your board also carries 3.3 V peripherals, the HCT input thresholds (0.8 V low, 2.0 V high) mean a 3.3 V CMOS output driving this latch may not reliably reach the high threshold — check the VOH of the driving device.
The 74HCT series has been in production for decades and remains a staple for 5 V logic, so the supply channel is mature. Store the reels dry (MSL 1 is typical for SOIC, but verify the label) and this part will sit on the shelf for years without issue.
16-SOIC package — footprint and rework
It is a gull-wing leaded package, easy to inspect and rework with a hot-air station. No exposed pad, no thermal vias needed — just standard decoupling near the supply pin.