The LM4857 is an integrated audio sub-system designed forstereo cell phone applications. Operating on a 3.3V supply, itcombines a stereo speaker amplifier delivering 495mW perchannel into an 8Ω load, a stereo headphone amplifier delivering33mW per channel into a 32Ω load, a mono earpieceamplifier delivering 43mW into a 32Ω load, and a line outputfor an external powered handsfree speaker. It integrates theaudio amplifiers, volume control, mixer, power managementcontrol, and National 3D enhancement all into a single package.In addition, the LM4857 routes and mixes the stereoand mono inputs into 16 distinct output modes. The LM4857is controlled through an I2C compatible interface. Other featuresinclude an ultra-low current shutdown mode and thermalshutdown protection.