Stereo codec switches for flexible audio

The world's first Class A/B to Class D switchable stereo codec is now available from Wolfson Microelectronics.

The world's first Class A/B to Class D switchable stereo codec is now available from Wolfson Microelectronics.

The WM8985 is targeted for use in mobile phones, MP3 players and wireless headsets and has an integrated dual mode headphone driver, dynamically switchable between Class A/B Class D drivers.

Class D increases efficiency by up to 70% and Class A/B mode provides additional flexibility to the designer.

"The WM8985 is the first product of its kind on the market to tap into the need for both audio quality and power savings needed for today's consumer audio products, including radios, mobile phones and RF-transmitting portable players", said Nat Edington, Wolfson Microelectronics Business Unit Manager.

As noted by Gartner analyst Stephen Ohr: "Class D amplifiers may be listenable at a fraction of their rated power".

"And just as Class A/B is a power-saving extension of Class A, the industry is hoping to render Class D as a power-saving extension of Class AB".

The high-performance codec is based on Wolfson's proven 897X platform and includes a built-in audio-enhancement DSP for wind noise filter, notch filter, five-band equaliser and 3D audio.

The WM8985 supports up to two differential microphone and analogue stereo line inputs, enabling direct mixing from an FM radio, and has two pairs of headphone drivers enabling two users on one audio player.

An integrated PLL supports input clock between 9 and 27MHz.

The WM8985 is available for sampling in a 32-pin QFN 5x5 (pin to pin compatible with 8976/8978).

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