Half-duplex RS-485 transceiver with 5 Mbps and 130 mV hysteresis
The Texas Instruments SN65HVD21DR is a half-duplex RS-485/RS-422 transceiver in an 8-SOIC package, rated for 5 Mbps signaling with 130 mV of receiver hysteresis.
At 5 Mbps the SN65HVD21DR can sustain a 200 ns bit period, which translates to roughly 400 m of cable at 5 Mbps before signal degradation forces a repeater. The 130 mV hysteresis on the receiver input cleans up noise on long stubs or in electrically noisy environments, so you get a clean logic level without external filtering on every node.
Supply and temperature — design-in checklist
The 8-SOIC footprint is a standard wide-body SOIC-8, so a layout already using that land pattern needs no board change.