Functional Description

The MT93L16 device contains two echo cancellers, as well as the many control functions necessary to operate the echo cancellers. One canceller is for acoustic speaker to microphone echo, and one for line echo cancellation. The MT93L16 provides clear signal transmission in both audio path directions to ensure reliable voice communication, even with low level signals. The MT93L16 does not use variable attenuators during double-talk or single-talk periods of speech, as do many other acoustic echo cancellers for speaker-phones

Features

• Contains two echo cancellers: 112ms acoustic echo canceller + 16ms line echo canceller

• Works with low cost voice codec. ITU-T G.711 or signed mag µ/A-Law, or linear 2’s comp

• Each port may operate in different format

• Advanced NLP design - full duplex speech with no switched loss on audio paths

• Fast re-convergence time: tracks changing echo environment quickly

• Adaptation algorithm converges even during Double-Talk

• Designed for exceptional performance in high background noise environments

• Provides protection against narrow-band signal divergence

• Howling prevention stops uncontrolled oscillation in high loop gain conditions

• Offset nulling of all PCM channels

• Serial micro-controller interface

• ST-BUS, GCI, or variable-rate SSI PCM interfaces

• User gain control provided for speaker path (-24dB to +21dB in 3dB steps)

• AGC on speaker path

• Handles up to 0 dB acoustic echo return loss and 0dB line ERL

• Transparent data transfer and mute options

• 20 MHz master clock operation

• Low power mode during PCM Bypass

• Bootloadable for future factory software upgrades

• 2.7V to 3.6V supply voltage; 5V-tolerant inputs

Applications

• Full duplex speaker-phone for digital telephone

• Echo cancellation for video conferencing

• Handsfree in automobile environment

• Full duplex speaker-phone for PC