WM8903

w WM8903 Ultra Low Power CODEC for Portable Audio Applications DESCRIPTION The WM8903 is a high performance ultra-low power stereo CODEC optimised for portable audio applications. The device features stereo ground-referenced headphone amplifiers using the Wolfson ‘Class W’ amplifier techniques incorporating an innovative dual-mode charge pump architecture - to optimise efficiency and power consumption during playback. The ground-referenced outputs eliminate headphone coupling capacitors. Both headphone and line outputs include common mode feedback paths to reject ground noise. Control sequences for audio path setup can be pre-loaded and executed by an integrated sequencer to reduce software driver development and eliminate pops and clicks via Wolfson’s SilentSwitch™ technology. The analogue input stage can be configured for single ended or differential inputs. Up to 3 stereo microphone or line inputs may be connected. The input impedance is constant with PGA gain setting. A stereo digital microphone interface is provided, which can also be mixed with the mic/line signals at the output mixers. A dynamic range controller provides compression and level control to support a wide range of portable recording applications. Anti-clip and quick release features offer good performance in the presence of loud impulsive noises. Common audio sampling frequencies are supported from a range of external clocks, either directly or generated via the Frequency Locked Loop (FLL). The WM8903 c...