The CY74FCT16543TPVC is a 16-bit non-inverting transceiver from the 74FCT logic family, organized as two 8-bit elements with independent direction and output-enable controls. The 3-state outputs let multiple transceivers share the same data bus, which is the usual configuration in a multiplexed address/data system. If your system lives in a climate-controlled rack, the commercial-grade sibling would also work, but this part gives you the margin without a cost premium on the 74FCT line.
56-BSSOP footprint — surface-mount only, no through-hole fallback
The package is a 56-lead BSSOP with 0.295-inch body width and 7.50mm pitch — the SSOP designation means the leads are gull-wing formed for surface-mount soldering. There is no through-hole equivalent in this series, so if your assembly line is mixed-technology, this part goes on the reflow side. The 56-SSOP supplier device package code matches the JEDEC MO-150 variation; the footprint is shared with many 56-pin bus-interface parts from TI and IDT, so a board layout for a 74ABT or 74LVTH 16-bit transceiver will usually accept this part without a respin.
Active and ROHS3 — no LTB clock ticking
The lifecycle status is Active, meaning Cypress (now part of Infineon) continues to manufacture this part with no announced end-of-life. The ROHS3 compliance covers all six original RoHS substances plus the four phthalates (DEHP, BBP, DBP, DIBP) under EU 2015/863, so there is no exemption-expiry risk to track for European or California-market builds.
Second-source reality — SN74ABT2245DW is a single-element 8-bit part, not a drop-in
The SN74ABT2245DW is often cited as a functional equivalent, but it is a single-element 8-bit transceiver versus this part's two-element 16-bit configuration. To replace one CY74FCT16543TPVC you would need two SN74ABT2245DW devices, doubling the footprint area and adding a second output-enable signal to the layout. The supply voltage and drive current match (4.5V–5.5V, 32mA/64mA), and both are surface-mount, but the board-level cost and space trade-off makes them a density alternative, not a pin-compatible second source.