What this transceiver does on the bus
The 1 Mbps data rate covers most Modbus RTU, BACnet MS/TP, and Profibus DP applications at typical baud rates, though it won't reach the 10 Mbps+ speeds of newer high-speed RS-485 parts.
35 mV hysteresis — why it matters on long cable runs
The receiver includes 35 mV of hysteresis, which is the built-in noise margin that prevents the output from chattering when the differential bus voltage is near the threshold. On a 1000-meter RS-485 run at 1 Mbps, ground-potential differences and reflections can push the received signal into the noise band; the hysteresis buys you enough deadband to keep the UART from seeing false start bits. For comparison, older SN75176-type parts have no specified hysteresis and rely entirely on external termination and biasing to achieve the same noise immunity.
The base product number 65HVD12 covers a family of speed and package variants, so if a future spin needs a different data rate or a smaller footprint, the migration stays within the same TI process node.