Single chip ANC solutions with integrated speaker driver ICs process external noise sensed by a microphone embedded in the headset, and generate a noise-cancelling signal, while amplifying the desired audio signal with very low levels of distortion.
With the introduction of the AS3421/22, ams has delivered an ANC solution optimized 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-analog design of the AS3421/22 is more efficient than DSP-based (digital) speaker driver ICs. The devices draw just 7 mA at 1.5 V 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 4 mm x 4 mm QFN24 package while the AS3422 uses a 5 mmx 5 mm QFN32 package.
Availability and Pricing
Sampling now, the price for the AS3421 ANC speaker driver IC is $2.15 in 1000-piece quantities; the price for the AS3422 is $2.70.
Evaluation kits for the AS3421 and AS3422 ANC speaker driver ICs are available.
More information about the AS4321 or AS3422 at www.ams.com/anc