Description

The MAX14857/MAX14859 isolated RS-485/RS-422 transceivers provide 5000VRMS (60s) of galvanic isolation between the cable-side (RS-485/RS-422 driver/receiver-side) and the UART-side of the device. Isolation improves communication by breaking ground loops andreduces noise when there are large differences in groundpotential between ports. These devices allow for robustcommunication up to 500kbps (MAX14857) or 25Mbps(MAX14859).The devices include an integrated 450kHz transformerdriver for power transfer to the cable-side of the transceiverusing an external transformer. An integrated LDO providesa simple and space-efficient architecture for providingpower to the cable-side of the IC.The devices include one drive channel and one receivechannel. The receiver is ¼-unit load, allowing up to 128transceivers on a common bus.Integrated true fail-safe circuitry ensures a logic-high onthe receiver output when inputs are shorted or open.Undervoltage lockout disables the driver when cable-sideor UART-side power supplies are below functional levels.The driver outputs and receiver inputs are protectedfrom ±35kV electrostatic discharge (ESD) to GNDB onthe cable-side, as specified by the Human Body Model(HBM).The MAX14857/MAX14859 are available in a wide body16-pin SOIC package and operate over the -40°C to +105°Ctemperature range.ApplicationsHVACIndustrial Automation EquipmentPower MetersProgrammable Logic Controllers