Cirrus Logic's WM8904 is a high-performance, ultra-low power stereo codec with stereo ground reference headphone amplifiers, combined with a dual mode charge pump architecture to optimize efficiency and power consumption during playback. The ground reference earphone and line output eliminate AC coupling capacitance, and both outputs include common mode feedback paths to suppress ground noise. The control sequence of audio path setting can be pre loaded and executed by the integrated control write sequencer to reduce software driver development and minimize pops and clicks. The analog input stage can be configured as a single ended or differential input. Up to three stereo microphones or line inputs can be connected. The input impedance is constant at the PGA gain setting. A stereo digital microphone interface with two input options is provided.
The Dynamic Range Controller (DRC) provides compression and level control to support a wide range of portable recording applications. The anti pinch and quick release functions provide excellent performance in the presence of huge pulse noise. ReTune mobile 5-band parametric equalizer is integrated with fully programmable coefficients to optimize speaker characteristics. Programmable dynamic range control is also available for maximum volume, protecting speakers from clipping and preventing premature shutdown due to battery droop.
WM8904 is used for applications including smart remote control, wireless and wired headphones, multimedia phones, palm games, our daily Bluetooth speakers, mobile Internet devices, netbooks and MP3 players
