Exar’s wireless UART chipset eliminates cables for serial or parallel interfaces

The XR18W750 supports both the parallel and serial interfaces to any host system, providing flexibility for system designers to select their interface option. Point-of-Sale (POS), security systems, data collection, data monitoring and other systems no longer need to be connected by serial cables, as the Exar wireless UART solution can transmit and receive data in point-to-point, and point-to-multi-point environments.

The wireless UART chipset comes with Exar's proprietary firmware that supports several communication modes including point-to-point, point-to-multi-point, and broadcast. Point-to-point mode allows exclusive communication between two wireless UART chipsets, similar to RS-232 communication. Point-to-multipoint mode allows communication between multiple wireless UARTs within the same network, similar to an RS-485 network. Broadcast mode sends data to any wireless UART chipset that is within range.

The XR18W753 is a single-chip RF transceiver designed to operate in license-free North American 915MHz ISM, European 868MHz SRD, and 950MHz to 956MHz bands for low-power, short-range wireless applications. The direct sequence spread spectrum (DSSS) technique is employed to provide robust data communication in signal congested RF environments. The device provides extensive hardware support for packet handling, data buffering, packet timing, RSSI, energy detection, link quality indication, clear channel assessment, FCS computation, and CRC detection. RF output power is programmable from -24 dBm to 0 dBm with a maximum data rate of 250Kbps.

The XR18W750 is a wireless UART controller with a two-wire I2C interface to the XR18W753 RF transceiver. The XR18W750 supports both the parallel and serial interfaces to any host system, providing flexibility for system designers. The XR18W750 includes an embedded 8051 microprocessor which provides the power to process the protocol framing for data transmission and to handle error processing. Internally, the XR18W750 has 4KB RAM for data processing. The XR18W750 also includes a 128-bit AES engine for data encoding and decoding.

Exar’s wireless UART chipset can be designed onto existing boards, or integrated into add-on wireless adapter cards providing wireless capabilities to systems currently using serial cables. The XR18W753 can also be used separately with popular Microcontroller Units (MCUs) via a simple two-wire I2C interface. The chipset is available in the industrial operating temperature range (-40 to +85oC) and is suited to industrial automation, factory automation, point of sales systems, industrial servers, data collection terminals and other industrial applications. Both ICs come in 48-pin QFN packages.