CMX138

Audio Scrambler and Sub-audio Signalling Processor

Features
  • Programmable Audio Scrambler
  • Full Audio-band Processing:
    Pre and De Emphasis
    Compandor
    Scrambler
    Selectable 2.55 and 3.0 kHz Filters
  • Auxiliary ADC and DAC
  • C-BUS Serial Control/Data Interface to Host µController
  • Two x Analogue Inputs (Mic. and Discriminator)
  • Selectable Audio Processing Order
  • CTCSS and DCS Sub-Audio Signalling
  • Auxiliary System Clock Output
  • Single-point Modulation Tx Output
  • Flexible Powersave Modes
Applications
  • Leisure Radio
    FRS, MURS, PMR446 and GMRS

Package Styles:
- CMX138E1 28-pin TSSOP

Supply Requirement:
3.0 to 3.6 Volts

Description
The CMX138 is a half-duplex audio scrambler and sub-audio signalling processor for analogue two-way radio applications. This makes it a suitable device for the leisure radio markets ( FRS, MURS, PMR446 and GMRS).

This device provides a user programmable frequency inversion audio scrambler with compnder and pre/de-emphasis - performing simultaneous processing of sub-audio and in-band signalling.

Other features include: an auxiliary ADC channel and an auxiliary DAC interface (with optional RAMDAC) to facilitate transmitter power ramping.
The device has flexible powersaving modes and is available in a 28-pin (E1) TSSOP package.