RS485/RS422 transceiver for industrial bus lines
The MAX13442EASA+T is a half-duplex transceiver supporting both RS422 and RS485 protocols at 250 kbps.
Receiver hysteresis and noise margin
Receiver hysteresis is specified at 25 mV, which provides a defined switching threshold and rejects differential noise on the bus. In a factory-floor RS485 run with common-mode shifts from motor drives, this hysteresis prevents the receiver from chattering on idle or unterminated lines. The half-duplex topology means the driver and receiver share the same bus pair; the transceiver must be enabled and disabled by the host UART's direction pin. The 250 kbps data rate is typical for Modbus RTU and other polled fieldbus protocols.