RS-485/RS-422 full-duplex transceiver for 5V industrial buses
5 Mbps signaling and 50 mV hysteresis — what they mean on the bus
At 5 Mbps the SN65HVD54DR handles Profibus and similar fieldbus rates without bit-rate limiting. The 50 mV receiver hysteresis provides a clean noise margin on differential lines subject to ground shifts and coupled interference — a practical advantage over parts with 20 mV or unspecified hysteresis when the cable runs exceed 100 meters or passes near VFDs. The full-duplex architecture means separate transmit and receive pairs, so no direction-control GPIO is needed; the driver enable can be tied high permanently.
14-SOIC footprint and supply rail
The 5V-only supply rail is a constraint — this part does not operate at 3.3V — so the design must carry a 5V bus or a local regulator. Decoupling with a 0.1 µF ceramic close to the supply pin is standard practice; the 50 mV hysteresis helps tolerate some supply ripple without false triggering.
There is no NRND notice, last-time-buy window, or successor part number on file.