The WM9094 is a low power audio subsystem that combines a headphone driver with a Class AB/Class D earpiece/speaker driver. The Class D speaker driver supports 650 mW output power at 3.6 V at 1%THD. A dual mode charge pump architecture provides ground referenced headphone outputs removing the requirement for external coupling capacitors. Class G technology increases efficiency and extends playback time by optimizing the headphone driver supply voltages according to the volume control. Mixers allow highly flexible routing to the outputs. Separate mixer and volume controls are provided for each headphone and speaker driver. Automatic Gain Control limits the speaker output signal in order to prevent clipping.