Cell Phone Speaker Driver Cancels Ambient Noise

When applied to mobile phones, the noise cancellation technology used in the WM2000 speaker driver enables users to make clear calls in noisy environments. The WM2000 is a low-power, high-quality receiver speaker driver built on the company’s myZone ambient noise cancellation (ANC) technology. MyZone is a new type of ANC technology that uses feed-forward, rather than the usual feedback systems, to provide up to 20 dB of noise cancellation during a call. It works without artificially boosting parts of the receive path frequency spectrum, and can do this across a 300-Hz to 2.5-kHz noise cancellation bandwidth. The WM2000 is the first single-chip version of this technology and has been designed to work in any handset platform design, regardless of form factor. The device is inserted between the output signal and the receiver circuit in the phone with minimal architecture changes. In addition, the WM2000 is highly power efficient, only switching on when required, reducing power consumption and increasing battery life. When noise cancellation is enabled, the WM2000 adds 20 mW to a voice call and on standby power is 8 µW. The WM2000 is sampling now in a CSP25 package and is priced at $3.50 in 1000-piece volumes. WOLFSON MICROELECTRONICS PLC, Edinburgh, UK, +44(0)131 272 7000.