Device identity and logic function
The 54S158FM is a TTL multiplexer with 2-line input, designed to select one of two data sources onto a single output line. This part belongs to the 54S series, a military-temperature-grade TTL family known for high-speed Schottky-clamped logic.
Lifecycle and compliance posture
Marked as Active in production status, the 54S158FM remains available for procurement through independent distribution channels. This component is RoHS non-compliant, a common characteristic of legacy TTL logic families that use lead-bearing solder terminations.
Packaging and sourcing considerations
Supplied in Bulk packaging, the 54S158FM is typically handled as loose units for through-hole assembly or prototyping, not tape-and-reel. For BOM integration, confirm the package outline against the existing PCB footprint — the 54S series uses a ceramic DIP or flat-pack format consistent with military-spec layouts.