ECHO Canceller Chip 1-CH G.711/G.712 Without Tone Detection 81-Pin CABGA Tray

The AEC section is comprised of an acoustic echo canceller, noise reduction and the operational control functions for operation. The AEC guarantees clear signal transmission in both transmit and receive audio path directions ensuring reliable voice communication even when low level signals are provided. The AEC does not use variable attenuators during double-talk or single-talk periods of speech, as do many other acoustic echo cancellers for speakerphones. Instead, the AEC provides high performance full-duplex operation similar to network echo cancellers. This results in users experiencing clear speech and uninterrupted background signals during the conversation and prevents subjective sound quality problems associated with “noise gating” or “noise contrasting”. The AEC uses an advanced adaptive filter algorithm that is double-talk stable, allowing convergence even while both parties are talking. This algorithm continually tracks changes in the echo path, regardless of double-talk, as long as a reference signal is available for the echo canceller. The echo tail cancellation capability of the acoustic echo canceller has been sized appropriately (127 ms) to cancel echo in an average sized office or large size car with a reverberation time of less than 127 ms.

• Handles up to -6 dB acoustic echo return loss
• 127 ms acoustic echo canceller
• Provides up to 12 dB of Noise Reduction
• Operate in two modes, Dual Analog mode and single Analog mode (other port is digital PCM)
• PCM Data Formats in single Port mode- 16-bit Linear, companded ITU-T A-law or U-law
• Advanced NLP design - full duplex speech with no switched loss on audio paths
• Tracks changing echo environment quickly
• Adaptation algorithm converges even during Double-Talk
• Designed for performance in high background noise environments
• Provides protection against narrow-band signal divergence
• Howling prevention eliminates uncontrolled oscillation in high loop gain conditions
• AGC on speaker path
• Transparent data transfer and mute options
• Boot loadable for future factory software upgrades
• Serial micro-controller interface
• Two 16 bit linear ACD and DAC that meet ITU-T G.711/712 recommendations
• Four Audio TX/RX Interfaces
• Differential Microphone Inputs
• Programmable Bias Voltage Output for Electret microphones
• Microphone Presence Detection, Microphone Mute