AMS, formerly Austriamicrosystems, has introduced two single chip active noise cancellation (ANC) solutions with integrated speaker driver ICs, which make it easier for manufacturers of Bluetooth headsets, headphones and earpieces to implement ANC.
The AS3421 and AS3422 are optimised for use in wireless headsets, many of which use Bluetooth to provide an RF channel between the host device and the headset. Low power consumption and long battery life are particularly important requirements in wireless headsets, and the all-analogue design of the AS3421/22 is markedly more efficient than DSP-based (digital) speaker driver ICs, says AMS. The devices draw just 7mA at 1.5V in stereo ANC mode, and <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 systems-on-chip, combining outstanding audio quality with high performance noise reduction of typically more than 25dB.
The AS3421 is housed in a 4mm x 4mm QFN24 package while the AS3422 uses a 5mmx 5mm QFN32 package.
According to Oliver Jones, Audio Marketing Manager at AMS: “Active noise cancellation brings an enormous improvement to the listener’s experience, but wireless headset manufacturers have been deterred from implementing it previously because of cost, power, size and weight concerns. With the introduction of the ultra-low power AS3421 and AS3422, which are almost a plug-and-play IC solution for Bluetooth headsets, manufacturers will now find it viable to bring the pleasure of noise-cancellation to the users of wire-free headsets, headphones and earphones.”