GMSK Modem and RF Transceiver
- Custom-Packet and Freeformat Modes
- Baseband and Integrated RF
- 4 to 16 kbps 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 and FCC CFR 47 Part 90
- Low-Power Operation with Powersaving
- Evaluation Kits Available
- 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
- CMX990Q1 64-pin VQFN
- 3.0 to 3.6 Volts
Operating in the range of 400MHz to 1GHz at data rates of 4 to 16 kbps. This single-chip, half-duplex device requires a minimum of external components, keeping end-product board size, power consumption and cost to an absolute minimum.
The CMX990 provides, on-chip: a flexible, formattable GMSK packet and freeformat modem, a dual synthesiser fed from an external source, IF and RF transceiver 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 are required to drive a power amplifier. In the Rx path, external circuits provide initial selectivity; 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 with NEW low pricing, in a no-leads, low profile 64 VQFN package.
Block Diagram
