CMX980A Digital-Radio Baseband Processor

The CMX980A is intended to act as an interface between the analogue and digital sections of a Digital Radio System, and performs many critical and DSP intensive functions.
The chip is designed with the necessary capability to meet the requirements for use in both mobile and basestation applications in Trans European Trunked RAdio (TETRA) systems.
The transmit path comprises all the circuitry required to convert digital data into suitably filtered analogue I and Q signals for subsequent up-conversion and transmission. This includes digital control of the output amplitudes, digital control of the output offsets and fully programmable digital filters; default coefficients provide the RRC response required for TETRA.
The receive section inputs differential analogue I and Q signals at baseband and converts this into a suitably filtered digital form for further processing and data extraction.
Facility is provided for digital offset correction and the digital filters are fully programmable with default coefficients providing the RRC response required for TETRA.
Auxiliary DAC and ADC functions are included to provide for control and measurement of the RF section of the radio system. This may include AFC, AGC, RSSI, or be used as part of the control system for a Cartesian Loop.

For further information please contact kellyb@spectre-online.co.uk