What this part is and where it fits
The MAX489CSD+ is a single-channel, full-duplex RS-422/RS-485 transceiver from Analog Devices (formerly Maxim Integrated). It handles one driver and one receiver in a 14-SOIC surface-mount package, with a maximum data rate of 250 kbps. The supply range is 4.75 V to 5.25 V, so it runs on a 5 V nominal rail—not 3.3 V. Operating temperature is 0°C to 70°C, making it a commercial-grade part for indoor equipment, office peripherals, and appliance control boards.
Key ratings and what they mean for the BOM
Data rate of 250 kbps is the practical ceiling for this transceiver. At that speed, the rise/fall times are slew-limited, which keeps radiated emissions low—useful for passing FCC/CE without extra filtering. If your bus runs at 115.2 kbps or below, this part has comfortable margin. Receiver hysteresis of 70 mV provides noise immunity on long cable runs. In a typical RS-485 network with 100 m of twisted pair, that hysteresis prevents chatter from ground shifts and reflections. Supply voltage is strictly 5 V ±5%. Do not try 3.3 V—the part is not specified there. Verify your rail is within 4.75 V to 5.25 V, especially if the board has a 5 V LDO with dropout headroom issues. Temperature range 0°C to 70°C covers office, lab, and consumer environments. Not rated for -40°C or +85°C, so skip it for outdoor telecom or under-hood automotive.
Lifecycle and sourcing reality
The MAX489CSD+ carries an Active lifecycle status per the manufacturer. It remains a standard catalog item through Analog Devices' distribution network.