RS-485 transceiver for industrial twisted-pair buses
For 3.3 V logic interfaces, level translation is needed on the driver and receiver enable pins — the part does not include internal logic-level shifting. The 1 Mbps data rate is a practical ceiling for most RS-485 applications; at lower baud rates (e.g., 115.2 kbps) the driver slew rate is still fast enough to cause ringing if termination is mismatched, so a 120 Ω resistor at each end of the bus is standard practice.