CMX990 GMSK Packet-Data Modem and RF Transceiver

Description
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 kbs, and is fully Mobitex compatible.

With a minimum of external components and circuits, this half-duplex device provides on-chip: a flexible, formattable GMSK packet and freeformat modem, a dual 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. The versatile GMSK modem is configured for either packet and freeformat data operation via an efficient task-oriented Rx and Tx format and command structure combined with data scrambling, interleaving and FEC and CRC capabilities. Rx data acquisition, extraction and tracking functions use Rx data-quality feedback to support varying signal environments. IF and RF functions in the Tx path handle all the signal processing required to generate GMSK modulation within an offset phase locked loop

A simple external loop filter and VCO are all that is required to drive a power amplifier. In the Rx path external circuits provide initial selectivity then the down conversion and IF processing are provided in the CMX990. An interface to an external IF filter is provided to allow selection of the appropriate channel bandwidth. System control and monitoring is comprehensively handled, internally and externally, via the 8-bit host interface, registers and on-chip ADCs and DACs. Requiring a low-power input in the range of 3.0 to 3.6 volts to its on-chip voltage regulator which supplies all the internal requirements with the addition of an external pass transistor, the CMX990 is available in a no-leads, low profile 64 VQFN package.
The CMX990 can be used in wireless products designed to comply with such standards as:
Mobitex, EN 300 113 and FCC CFR 47 Part 90.

Resources: datasheet \| data updates \| FAQs \| application notes \| innovations \| evaluation: ev9900A \| ev9902 \|
Quantity Price Guide: $10.83

Features Mobitex, Custom-Packet and Freeformat Modes Baseband and Integrated RF 4 to 16kbps GMSK Modulation at BT of 0.3 or 0.5 Full-Feature Airlink Frame Formatting (plus FEC, CRC, Interleaving and Scrambling) Integrated RF, IF and Synthesiser Sections (400MHz to 1GHz Range) Dual Integer-N Synthesisers On-Chip ADCs and DACs Simple Parallel Interface Versatile System Clocks Suitable for EN 300 113, FCC CFR 47 Part 90 and Mobitex Applications Low-Power Operation with Powersaving Demonstration and Evaluation Kits Available	Applications Narrowband Data-Over-Radio M2M Data Communications Radio Modems Mobitex Data Systems (Base and Mobile) Wireless Telemetry SCADA Terminals Mobitex, EN300 113 CFR 47 Part 90 Applications Package Styles: CMX990 Q1 64-pin VQFN Package Supply Requirement: 3.0 to 3.6 Volts

Description 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 kbs, and is fully Mobitex compatible. With a minimum of external components and circuits, this half-duplex device provides on-chip: a flexible, formattable GMSK packet and freeformat modem, a dual 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. The versatile GMSK modem is configured for either packet and freeformat data operation via an efficient task-oriented Rx and Tx format and command structure combined with data scrambling, interleaving and FEC and CRC capabilities. Rx data acquisition, extraction and tracking functions use Rx data-quality feedback to support varying signal environments. IF and RF functions in the Tx path handle all the signal processing required to generate GMSK modulation within an offset phase locked loop A simple external loop filter and VCO are all that is required to drive a power amplifier. In the Rx path external circuits provide initial selectivity then the down conversion and IF processing are provided in the CMX990. An interface to an external IF filter is provided to allow selection of the appropriate channel bandwidth. System control and monitoring is comprehensively handled, internally and externally, via the 8-bit host interface, registers and on-chip ADCs and DACs. Requiring a low-power input in the range of 3.0 to 3.6 volts to its on-chip voltage regulator which supplies all the internal requirements with the addition of an external pass transistor, the CMX990 is available in a no-leads, low profile 64 VQFN package. The CMX990 can be used in wireless products designed to comply with such standards as: Mobitex, EN 300 113 and FCC CFR 47 Part 90.

CMX990

GMSK Modem and RF Transceiver