Maxim’s MAX3471 is half-duplex transceiver intended for lithium battery-powered RS-485/RS-422 applications. It draws only 1.6 µA (typical) supply current from a 3.6 V supply with the receiver enabled and the driver disabled. Its wide 2.5 V to 5.5 V supply voltage guarantees operation over the lifetime of a lithium battery. The MAX3471 device features true fail-safe operation that guarantees a logic-high receiver output when the receiver inputs are open or shorted. This means that the receiver output will be logic high if all transmitters on a terminated bus are disabled (high impedance). The MAX3471 has a 1/8-unit load input resistance. When driver outputs are enabled and pulled above V_CC or below GND, internal circuitry prevents battery back-charging.