ADM485JRZ (ANALOG DEVICES)

The ADM485JRZ is a Low Power EIA RS-485 Transceiver suitable for high speed bidirectional data communication on multipoint bus transmission lines. It has dedicated differential line driver outputs and receiver inputs. Both the driver and the receiver can be enabled independently. Excessive power dissipation caused by bus contention or by output shorting is prevented by a thermal shutdown circuit. If during fault conditions, a significant temperature increase is detected in the internal driver circuitry, this feature forces the driver output into a high impedance state. Up to 32 transceivers can be connected simultaneously on a bus, but only one driver should be enabled at any time. It is important, therefore, that the remaining disabled drivers do not load the bus. The receiver contains a fail-safe feature that results in a logic high output state if the inputs are unconnected (floating).