The SN74LS644DW is an LS-series TTL bus transceiver from Texas Instruments. It handles bidirectional data flow between two buses, a standard function for legacy 5 V logic systems found in industrial controllers, telecom line cards, and older embedded designs.
RoHS flag — check your assembly line
This part is RoHS non-compliant. If your production line runs lead-free reflow profiles, the SN74LS644DW will need an exemption or a separate hand-solder / wave-solder step. For legacy boards originally built with tin-lead solder, it's a direct drop-in — no process change needed.
Sourcing posture
No last-time-buy or end-of-life risk on this line today.