CMX881

Baseband Processor for PMR and Trunked Radios

Features
  • Standard CTCSS Tone Generation and Detection
  • Automatic Signal Scanning and IRQ on Detection of Valid Rx Signals
  • Tone Generation for Caller Recognition Tunes
  • Low Power Operation with Graduated Powersave
  • Programmable Signal Detection Thresholds
  • Aux ADC Available to Monitor Inputs
  • Programmable Selcall Codec
  • Meets ETS 300 086, MPT1327, PAA and ETS 300 230 Specs
  • Voice Processing Facilities: Tx and Rx
  • Path Gain Setting, Voiceband and Sub-Audio
  • Filtering, Programmable Soft Limiter
  • C-BUS Serial Host Interface
  • Tx Interface for Single or Two-Point Modulation
  • DTMF Generation
Applications
  • PMR Radio Systems
  • Trunked Radio Systems
  • Wireless Signalling

Package Styles:
- CMX881D6  - CMX881E1

Supply Requirement:
2.7 - 5.5 Volts

Description
The CMX881 is a full-function half-duplex audio and signalling 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 b/s 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 solutions, is available in compact SSOP and TSSOP packages.