What this 74FCT transceiver does — and what it doesn't
The CY74FCT2543CTQCT is a single-element, 8-bit non-inverting transceiver from the 74FCT logic family, with 3-state outputs. It operates from a 4.75V to 5.25V supply, making it a direct fit for legacy 5V TTL/CMOS buses where a 3.3V part would leave no noise margin.
Output drive — 15mA / 12mA: enough for a loaded bus?
High-level output current is 15mA, low-level is 12mA. That's typical for the 74FCT family — adequate for driving a few TTL loads or a short backplane trace, but not for heavy fan-out or long cables. If your design needs 32mA per pin, the SN74ABT2245DW is a closer match, though it runs on a 4.5V supply and comes in a larger SOIC package. The 15mA / 12mA rating also means the part is not intended for high-current line driving; keep the trace length under a few inches at 5V to avoid signal degradation.
It is not AEC-Q100 qualified, so avoid under-hood or chassis-domain automotive applications without additional screening. The 5V-only supply also rules out battery-powered portable gear where 3.3V or lower rails dominate.
ROHS3 compliant, so it passes EU material restrictions without an exemption.