What this RS485/RS422 transceiver is — and what it needs from your rail
The 50 mV of receiver hysteresis buys you noise margin on long twisted-pair runs without external filtering. It will not run on a 3.3 V rail — if your system is 3.3 V only, you need a different transceiver (the SN65HVD30 family operates at 3.3 V).
25 Mbps full-duplex — what the data rate and duplex mode mean for your bus
Full-duplex operation means the SN65HVD50D can transmit and receive simultaneously, using separate twisted pairs. This doubles the throughput compared to half-duplex RS485 implementations that must arbitrate the bus direction. At 25 Mbps, the bit period is 40 ns — the driver slew rate is fast enough to hit that rate, but you need controlled-impedance cabling (120 Ω termination) and stub lengths kept under a few inches to avoid reflections. The single driver and single receiver (1/1 count) match point-to-point or small multi-drop topologies. For larger multi-drop networks with more than 32 unit loads, consider a transceiver with higher receiver input impedance.
Package and footprint — 8-SOIC narrow-body land pattern
Standard SOIC-8 footprint; no thermal pad to worry about.