CMX990

Features:

· Single Chip RF Transceiver and GMSK Modem
· IF, RF, Control and Synthesizer Stages
· Selectable Bt = 0.3 or 0.5
· Full Mobitex Compatibility
· Packet and Freeformat (Raw) Data
· Versatile Data Rates: 4kbps to 16kbps
· Simple Parallel Interfacing
· Low-Power, Low Profile, Low-Cost BOM
· Flexible System Clocks




Application

· Narrowband Data Over Radio
· Mobitex Data Terminals
· 400MHz to 1GHz Radio Data Systems
· Radio Modems
· Wireless Telemetry
· SCADA Terminals
· Suitable for EN 300 113 and FCC CFR 47 Part 90 Applications





Specifications






Description

A single-chip GMSK packet-data modem and RF transceiver, the CMX990 provides the majority of circuits and functions, including host µC interfaces, to implement a full-feature 'wireless modem' subsystem. The CMX990 can operate in RF ranges of 400MHz to 1GHz at data rates of 4 to 16 kbps and is fully Mobitex compatible.
With a minimum of external components and circuits CMX990, this half-duplex device provides on-chip: a flexible, formattable GMSK packet and freeformat modem, a dual operation synthesiser fed from an external source, IF and RF stages for both Rx and Tx modes, and auxiliary ADCs and DACs for system control and monitoring.
This versatile GMSK modem is programmable to both packet and freeformat data operations via an efficient task-oriented Rx and Tx format and command structure, which is combined with data scrambling, interleaving and FEC and CRC capabilities. Rx data acquisition, extraction and tracking abilities, allied with Rx data quality feedback, allow the CMX990 to operate seamlessly in varying signal environments.
CMX990 IF and RF functions in the Tx path handle all the required signal mixing and up-conversion to produce the FM modulation for the final external PA circuitry. In the Rx path these circuits provide initial selectivity and rejection characteristics and mix down the inputs to provide baseband signals for the modem.
Comprehensive internal and external system control and monitoring is provided by the 8-bit host interface registers and the on-chip ADCs and DACs. Requiring a power supply input in the range 3.0 to 3.6 Volts, the CMX990 can be used in wireless products designed to comply with such standards as EN 300 113 and FCC CFR 47 Part 90. Operating over a temperature range of -40°C to +85°C, the CMX990 consolidates the core radio modem functions to enable a new generation of small, narrow-band wireless data modems. The CMX990 comes in a 64-pin low profile VQFN package.