Wireless headsets, which may be linked over the air to devices such as mobile phones and portable media players, are often used in noisy environments such as cars, airplanes, office buildings and public places. The successful implementation of ANC dramatically reduces the perceived volume of external noise, enabling the desired receive-path audio signal to be heard against a nearly silent background, explained the company.

With the introduction of the AS3421/22, the ANC solution is now optimized for wireless headsets, many of which use Bluetooth to provide an RF channel between the host device and the headset, ams noted.

Low power consumption and long battery life are particularly important requirements in wireless headsets, and the all-analog design of the AS3421/22 is markedly more efficient than DSP-based (digital) speaker driver ICs. The devices draw 7mA at 1.5V in stereo ANC mode, and less than 1µA in quiescent mode. They also implement an ultra-low power ANC-bypass mode when the user selects the playback-only function.

In addition, the AS3421/22 devices offer fully differential stereo line inputs to match the differential line outputs from typical Bluetooth-based headset SoCs, combining outstanding audio quality with high performance noise reduction of typically more than 25dB.

The AS3421 and AS3422 ANC speaker driver ICs are available in 1000-piece quantities.