CMX882E1

Product Description

The CMX882 is a full-function half-duplex audio and signalling processor IC for FRS and PMR446 type facilities suitable for both complex and simple end-designs. Under the control of the host µC, all voiceband requirements are catered for: voiceband and sub-audio filtering, pre/de-emphasis, compression and expansion and audio routing and global level setting with single or two-point modulation in the transmit path.

The combination of new and standard signalling functions of this product offer, under software control, increased functionality, versatility and privacy. Standard Extended-Code CTCSS and DCS functions are integrated with the new XTCSS code implementation. XTCSS provides additional and improved squelch-centred privacy codes with the added advantage of silent operation; no annoying interference from other sub-audio users. XTCSS fitted radios enjoy more privacy and flexibility of operation.

For advanced and enhanced radio operation, the CMX882 provides a 1200/2400 bps free-format and packet data FFSK/MSK modem for text messaging/paging, passing GPS location data (compatible with NMEA 0183) and other data applications.

With ultra low power requirements and graduated powersave, this product only requires a smaller, lower-power µC than existing FRS/PMR446 solutions.

Features

• Full-Feature Audio-Processing, Signalling and GPS Data for Half Duplex FRS, MURS, PMR446 and GMRS Leisure Radios
• Automatic signal type scanning and IRQ on detection of valid Rx signals, level or RSSI
• Voice processing facilities, including Tx and Rx gain setting and voice/subaudio filtering
• Voice processing facilities, including Tx and Rx gain setting and voice/subaudio filtering
• Tone generator for caller recognition tunes
• Programmable powerdown control, Programmable signal detection thresholds.
• XTCSS channel and data signalling
• Robust automatic packet data protocol with: Error correction and detection, Interleaving and data scrambling/privacy coding.
• Low Power operation with Zero Power mode
• Uncommitted Aux ADC with switchable input to monitor signals