Speaker driver provides ANC in Android smartphone

2nd March 2015

Nat Bowers

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ams has announced that the headset in the latest Huawei smartphone, the Ascend Mate 7, implements advanced noise cancellation with the company's AS3415. The high-end Android smartphone takes advantage of the ANC (Active Noise Cancellation) capability of the speaker driver to attenuate a large proportion of ambient noise from low frequencies up to around 3kHz.

The method of combating ambient noise commonly adopted by users of conventional earphones is to turn up the volume very high. This achieves a higher signal-to-ambient-noise ratio, but at the risk of damaging the sensitive inner ear. With the Ascend Mate 7’s headset - due to the provision of noise-cancelling earphones - every audio signal can be heard easily when played at a comfortable volume. Combined with the passive noise reduction provided by the in-ear housings surrounding the speakers, this provides the user with an immersive listening experience, undistracted by extraneous sounds.

The high-performance ANC implementation enabled by the AS3415 also makes the Ascend Mate 7 more enjoyable to use in voice calls: users accustomed to straining to understand the other party’s voice on phone calls in noisy environments will notice how much easier it is to talk in the near-silent background provided by the ams ANC technology.

The AS3415, a feed-forward ANC speaker driver IC, is a perfect fit for the Ascend Mate 7’s headset because of its low power consumption, outstanding audio performance and small size. Unlike competing ANC systems, which contain a digital signal processor that runs software to shape the speaker’s output signal, ams speaker drivers use pure analogue circuitry. This uses less than half the power of digital ANC systems. It also saves space in the headset, because all the features necessary for noise cancellation are integrated into the AS3415’s circuitry, with very few, small external components required.

The high-fidelity sound reproduction of the AS3415 also helps the Ascend Mate 7’s headset to achieve superior audio quality. The AS3415 produces typical total harmonic distortion of just 0.004%, and offers a signal-to-noise ratio of less than 110dB (34mW output into a 32Ω load). Typical active noise attenuation achieved by the AS3415 is 95%.

"Huawei has made a breakthrough in the consumer appeal of high-end smartphones by providing ANC in the headset of the new Ascend Mate 7. Users will love the crystal-clear audio and almost totally silent background enabled by the AS3415 ANC speaker driver in the headset," said Oliver Jones, Director and General Manager, Audio Sensors, ams.

The AS3415 is available immediately in production volumes. An evaluation kit for the AS3415 ANC speaker driver is also available.