True Fail Safe Line Receiver RS422, RS485, 3V to 5.5V Supply, SOT-23-5 - 

The MAX3280EAUK+T is a ±15KV ESD protected 52Mbps, 3V to 5.5V, RS485/RS422 true fail-safe receiver in 5 pin SOT-23 package. It is a single receiver designed for RS485 and RS422 communication, the true fail-safe circuitry gives a logic-high receiver output when the receiver inputs are opened or shorted and receiver output will be a logic high if all transmitters on a terminated bus are disabled (high impedance). This device characterizes 1/4-unit-load receiver input impedance allowing up to 128 receivers on the same bus.