Abstract
In recent years, class D audio amplifiers which are based on switch mode are becoming more and more feasible for their property of high efficiency , low-power, low-THD and small-structure in comparison to traditional analogy class D audio amplifiers. In this thesis I mainly have been analysed the work of class D audio amplifiers as well as their basic features in mathematical. What is more, I also analysed the composition and function of the system. To design a class D audio amplifier with perfect-function and well-performance, it is used half-bridge structure in output stage and high-performance integrated driving chip in driving output circuit. In this work, it adopts a pair of sources and one triangular wave circuit to design two-channel stereo. The process of class D audio amplifiers' implementation can be depicted as follow: an analog audio signal is compared with a high frequency carrier to generate a switching wave(PWM). Then it is changed into digital pulse to drive high-speed switching circuit, in order to increase the current and voltage of input signal.Finally it is passed through a low-pass filter to recover the analog wave and eliminate the high frequency components.
Keywords： Class D Amplifier；PWM；Triangle Wave；Comparator Filterin
