Digital Voice Systems, Inc.

AMBE-4020 Vocoder Chip

Building on DVSI’s line of compact vocoder chip solutions the AMBE-4020™ chips deliver performance and reliability that meet the harsh demands of digital communication systems.

The AMBE-4020™ chips feature DVSI’s patented AMBE+2™ Voice Compression Algorithm. With the flexibility of operating at data and FEC rates from 2.0 to 9.6 kbps users can optimize system design to provide excellent voice quality with superior robustness to bit errors and acoustic background noise.

The AMBE-4020™ FD (full-duplex) and the AMBE-4020™ (halfduplex) chips offer many attractive features including low-cost, high-quality voice, noise suppression, many data rate & FEC combinations.

The value of DVSI’s AMBE® Voice Compression Technology goes beyond low bit rate and voice quality. It has been thoroughly evaluated and tested by international manufacturers under various conditions using a variety of languages. This assures the user is getting the best vocoder available and makes the DVSI vocoder the logical choice without the need for additional comparison tests. Plus the fact, that DVSI’s Voice Compression technology has been implemented worldwide for more than 25 years, delivers the added security of a field proven technology that can play a key role in making any communication system an overall success.


  • Low cost
  • High voice quality
  • Noise suppression
  • AMBE+2
  • Low data rate


  • Superior voice quality, DVSI’s latest generation half duplex AMBE+2™ Vocoder Technology
  • Maximizes channel bandwidth efficiency supports data-rates from 2.0 kbps to 9.6 kbps
  • The AMBE-4020™ Full-Duplex model supports echo cancellation
  • The AMBE-4020™ Half-Duplex model supports Push-to-talk Operation
  • User selectable forward error correction rates – 50 bps to 7.2 kbps

  • Excellent performance at low data rates and harsh environments
  • Robustness to acoustic background noise and channel bit errors
  • Advanced features like Noise Suppression, Improved Error Mitigation, and Soft Decision FEC Decoding
  • Supports a-law and u-law companding via I2S interface
  • DTMF detection and regeneration with North American call progress tones


  • Full-Duplex and Half-Duplex models are available
  • 80 pin 12mm x 12mm LQFP small package design
  • Integrated ADC/DAC for quality audio I/O
  • Also can be interfaced with most low-cost A/D-D/A codecs
  • Input Interfaces include, internal ADC or digital mic or I2S
  • Output interfaces include: internal DAC or I2S
  • Interface for low-cost digital microphone
  • Very low power consumption – Ideal for portable mobile devices
  • Small compact footprint design
  • No licensing fees or royalties
  • Off-the-shelf availability for quick delivery

Contact Information

Digital Voice Systems, Inc.

234 Littleton Road, Suite 2E
Westford, MA , 01886

tele: (978)392-0002
fax: (978)392-0002

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