Maxim Integrated Products introduces the MAX9877, a small audio subsystem that combines a high-efficiency, high-power, mono Class D speaker amplifier, a DirectDrive, stereo headphone amplifier and a low-noise, bypass analog switch. In addition to this integration, the device uses a proprietary third-generation, ultra-low EMI Class D amplifier technology to provide Class AB audio performance with Class D efficiency. It delivers 725 mW of output power from a 3.7 V supply into an 8 ? load with 85% (max.) efficiency. Providing high output power from a lithium-ion battery, the subsystem is suitable for cellular phones, portable media players (PMPs) and other applications that require high audio quality, output power and efficiency. All controls are enabled through an I²C interface.