MAX14949

The MAX14949 isolated RS-485/RS-422 transceiver provides 5000V_RMS (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 and reduces noise when there are large differences in ground potential between ports. This device allows for robust communication up to 500kbps.

The device includes an integrated 450kHz transformer driver for power transfer to the cable side of the transceiver using an external transformer. An integrated LDO provides a simple and space-efficient architecture for providing power to the cable side of the IC.

The device includes one half-duplex driver/receiver channel. The receiver is 1/8-unit load, allowing up to 256 transceivers on a common bus.

Integrated true fail-safe circuitry ensures a logic-high on the receiver output when inputs are shorted or open. Undervoltage lockout disables the driver when cable-side or UART-side power supplies are below functional levels.

The driver outputs/receiver inputs are protected from ±30kV electrostatic discharge (ESD) to GNDB on the cable side, as specified by the Human Body Model (HBM).

The MAX14949 is available in a wide body 16-pin SOIC package and operates over the -40°C to +85°C temperature range.

Applications

• HVAC
• Industrial Automation Equipment
• Power Meters
• Programmable Logic Controllers