74FCT543ASPC is a bus transceiver from the FCT series, providing bidirectional data transfer between two buses.
This is a straightforward line item to qualify for new designs or ongoing production. One catch: the part is RoHS non-compliant, meaning it uses lead-bearing solder terminations. If your assembly line is RoHS-exempt (mil/aero, medical, or high-rel with leaded solder exemption), this is a non-issue. For RoHS-mandated builds, you will need to source a lead-free alternate — the FCT series includes several Pb-free variants, though no direct drop-in is listed here.