Full-duplex RS422/RS485 at 250 kbps — single-channel bus interface
The MAX489ECSD+T: This is a single-channel full-duplex transceiver with one driver and one receiver (1/1 configuration). Full-duplex means the device can transmit and receive simultaneously on separate twisted-pair wires — useful for point-to-point or multi-drop RS422 links where the bus topology supports separate transmit and receive pairs. Data rate is 250 kbps, placing it in the low-to-medium speed band for RS485 networks. At this rate, cable length can reach 4000 feet without significant signal degradation on properly terminated lines — the trade-off is throughput vs reach. Receiver hysteresis of 70 mV provides noise margin on the differential bus. In electrically noisy environments — motor drives, inverter lines, industrial panels — this hysteresis prevents the receiver from oscillating on slow or noisy edges.
5V supply, commercial temperature — indoor / controlled-environment duty
This is not a wide-VIN part; the 5V rail must be regulated. The 70 mV hysteresis helps tolerate some ripple on the supply, but the transceiver expects a clean 5V bus. This limits deployment to indoor, climate-controlled environments: office equipment, telecom racks, test equipment, or factory-floor cabinets with HVAC. Not suitable for outdoor, under-hood, or unheated enclosures. Packaged in 14-SOIC (narrow-body, 3.90 mm width) — a standard footprint for small-signal interface ICs. The tape-and-reel variant (T suffix) is suited for automated pick-and-place assembly; cut-tape also available for prototype runs.