The CMX881 is a full-function half-duplex audio and signalling baseband processor IC for both PMR and trunked radio systems and is implementable to complex and simple end-designs.
Under the control of the host µC, all voiceband requirements are catered for:
Voiceband and Sub-audio filtering, Pre/de-emphasis and audio routing and global level setting with single or two-point modulation in the transmit path.
The combination of new and standard signalling functions of this product offer, under software control, increased functionality, versatility and privacy:
Standard Code CTCSS and DCS functions and selcall operation.
To cater for call setup and system signalling the CMX881 offers an embedded 1200/2400 bps MSK/FFSK freeformat modem with sync detection in the Rx path and MPT standard CRC operations in Tx/Rx modes.
With ultra low power requirements and graduated powersave, this product therefore requires a smaller, more low-power µC than existing PMR or trunked radio systems, is available in compact SSOP and TSSOP packages.
Devices are available through our distributors below:
Guides to operation and interfacing