After entering the 2 1 century, various portable electronic devices have become an important development trend of electronic devices. From the mobile phone as a communication tool to the MP3 player as an entertainment device, it has become a portable electronic device for almost everyone. Portable TV sets, portable DVDs, etc. will be popularized one after another. What all these portable electronic devices have in common is that they all have audio output, that is, they all need an audio amplifier; Another feature is that they are all battery-powered. Everyone wants to have a long service life. It is under this background that class D amplifier is developed. Its biggest feature is that it can get the highest efficiency with the lowest distortion.

High-efficiency audio amplifier is needed not only in portable devices, but also in high-power electronic devices. Because the greater the power, the more important the efficiency. With the improvement of people's living conditions, high-fidelity audio equipment and higher-grade home theaters have gradually begun to rise. In these devices, tens or even hundreds of watts of audio power are often needed. At this time, the audio amplifier with low distortion and high efficiency becomes the key component.