dPMR operation includes vocoder connectivity (RALCWI – CMX618 and AMBE+2 – AMBE3000), a 4FSK modem with automated frame sync detection and 4.8kbps data rate, and both physical layer and data-link layer air interfaces. This highly integrated functionality minimises host controller interactions to reduce power consumption. It enables the longest battery life for a dPMR radio, claims the device manufacturer, CML Microcircuits.
In analogue mode, the CMX7131 and CMX7141 integrate analogue audio processing with a selectable compandor and scrambler, 12.5kHz and 25kHz channel filters, pre- and de-emphasis, and limiters. For external signaling support both CTCSS and DCS filters are also built in.
Other features include two auxiliary ADCs with four selectable inputs, and four DAC interfaces. The CMX7131 additionally features two on-chip RF synthesizers, with easy receive/transmit switching.
Both devices have flexible power-saving modes and each is available in either LQFP or VQFN packages.
The ATB010 dPMR RF demonstrator board is also available. This can be helpful in reducing design and development time.