If your UART or controller runs at 5V, you need level translation on the logic-side pins (DI, DE, RE, RO). The receiver outputs and driver inputs are 3.3V-tolerant, but feeding 5V into the supply pin exceeds the absolute maximum and will let the smoke out.
Data rate and bus timing margin
Rated for 50 Mbps, this transceiver handles high-speed backplane or short-haul RS-485 links where propagation delay and skew matter. At that rate, stub length and termination become critical — expect to use 120 Ω termination at both ends of the bus and keep stubs under 6 inches to avoid reflections that eat into the timing budget. The full-duplex capability lets you run transmit and receive pairs simultaneously, which halves the cable count compared to half-duplex in a point-to-point link.
The 10-VSSOP package is small (3.00 mm width), so thermal dissipation is limited; in a 125°C ambient, keep the driver duty cycle below 50% or add airflow to stay inside the junction temperature limit.