Conexant launches 4-channel USB voice capture IC

USA: Conexant Systems Inc. has introduced the CX20820, its new high-performance USB voice capture IC targeted to voice interactive products, voice conferencing systems, Skype TV/STB webcam, and surveillance applications.

The CX20820 is the industry’s first USB Microphone analog-to-digital converter (ADC) with integrated preamplifier, gain calibration, and sync control. This product is a part of Conexant’s extensive portfolio of Voice Capture Products, enabling a best-in-class performance.

The isochronous, full-speed USB interface provides universal compatibility with major CE devices and appliances, making it easy to add state-of-the-art voice capture capability to existing hardware and OS platforms. The integrated Sync Control feature eliminates clock jitter by synchronizing the ADC to the playback clock domain, a critical advantage for systems running acoustic echo cancellation algorithms.

There are a total of four independent voice input channels with integrated anti-aliasing filters for microphone array applications. The major challenge with microphone arrays, which are used for voice localization and beamforming, is unmatched microphones in an assembled microphone module. This problem often leads to inaccurate estimation of the shape of the beam, and issues in noise suppression and precision localization.

The CX20820 includes a self-gain calibration feature that corrects for the mismatch down to maximum 1 dB variance—another innovation in the CX20820 that stands out from the typical microphone ADC.