The CS47L15 is a smart audio codec with expanded audio features, such as always on voice activation, enhanced karaoke (KTV) and virtual stereo for smartphones beyond flagship models. Pro-audio filters enable high fidelity headphone and speaker playback and low power analog and digital interfaces provide flexible support of the DSP core to enable advanced audio processing functions such as speaker protection and acoustic echo cancelation (AEC). A fully integrated audio subsystem featuring Cirrus Logic's proprietary SmartHIFI? offers high resolution HD audio playback and a low output impedance offers natural audio reproduction independent of the headphone make and model. A 30mW stereo headphone/earpiece/line output driver provides ground-referenced output with noise levels as low as 0.45 VRMS and just 0.1% total harmonic distortion (THD+N). A 2.5W Class D driver can enable an extended stereo region for the earpiece speaker with two channels of stereo PDM output to match the louder boosted amplifier. The device is powered from 1.8V and 1.2V supplies and the power, clocking and output driver architectures are designed to maximize battery life in voice, music and standby modes. Wideband noise reduction and speech enhancement are also provided.