Zarlink AEC reduces noise in hands-free communication apps

Zarlink Semiconductor introduced the second in a family of voice processing devices that promises to improve voice quality and reduce noise in a wide range of hands-free communication applications, including car kits, desktop phones and intercom systems.

According to the press release, the ZL38003 AEC (acoustic echo canceller) builds on an algorithm designed to track and reduce background noise and preserve voice quality in high-noise environments. The chip offers hands-free equipment designers an integrated solution that helps reduce design complexity, component costs and board space requirements.

"Voice quality often suffers when designers strike a balance between system cost, design complexity and integration concerns," said Andre Coucopoulos, marketing manage for voice processing at Zarlink. "The ZL38003 chip bundles a proven algorithm that handles hands-free voice performance issues, such as double-talk problems that often plague competing solutions, with features that meet design cost and integration demands."

The ZL38003 AEC's integrated features, including codecs, programmable gain pads and a four-port cross-point switch, eliminate the need for many external components. The chip's two 16-bit linear codecs deliver performance that exceeds competing a/law and u/law codec designs by achieving better algorithm and acoustic echo cancellation performance, lower noise level and fewer non-linearity effects, added the company.

When used in a desktop phone design, the integrated four-port cross-point switch allows the analog signal to be directed to any of the four ports which can be connected to a headset, speaker, ringer and audio jacks. The integrated switch helps save design time and board space by eliminating the need to include and configure an external device.

The programmable gain feature allows the user to adjust a wide range of transducer sensitivities, with two microphone amplifiers and four earpiece amplifiers enabling connection to a handset, headset, auxiliary channel and microphone/speaker. Additional features include anti-howling detection that identifies instability in the audio path and automatically avoids oscillation.

The ZL38003 device is available in an 81-ball CABGA (chip array ball grid array) package measuring 10-by-10mm. The chip is fully supported by an evaluation board, hands-free car kit application board and API software.