基于D类的数字功率放大器设计毕业论文.doc

毕业设计论文 基于D类的数字功率放大器设计 摘 要 音频功率放大器是功率集成电路中的一个重要组成部分，并且广泛应用于消费类电子产品中。我国是全球最大的消费类电子商品市场和生产基地，音频功放的需求日益增加，因此研究音频功率放大器具有非常重要的意义。 随着科学技术的不断发展，尤其是集成电路技术的发展，高速、大功率器件已越来越多，移动电话、数字媒体技术、平面电视、便携式数字产品等电子产品正在向薄型化、便携式迅速发展，人们对音频功率放大器的要求更加趋向于高效、节能和小型化。因为移动设备受电池容量、散热、体积的限制，对音频功率放大器要求高效、节能、发热量少、体积小、便于集成。 传统的模拟音频功率放大器虽然具有很高的保真度，但是却存在功耗高、效率低等致命缺点，而且发热量大，不易解决散热问题。而D类放大器由于工作在开关状态，作为控制元件的晶体管本身消耗功率较低，所以功放的效率很高。与传统的AB类音频功率放大器相比，数字D类音频功放最大的优势在于具有高效率，实际转换效率能达到80％以上，理论转换效率可以达到100%。因此能极大地降低能源损耗，减小放大器体积。在这个能源节约的时代，凭借其高效率、低功耗的特点，数字D类音频功放正逐渐取代传统的模拟音频功率放大器，并越来越受到人们的重视。本文论述了各种音频功率放大器的工作原理以及各自的性能特点，重点阐述了D类音频功率放大器的工作原理和脉宽调制工作原理，并在此基础上设计一款大功率输出、低功耗数字音频D类功率放大器。 关键词：音频功率放大器；D类；脉宽调制 Abstract Audio power amplifier is an important part of PIC(Power Integrated circuits)which is widely used in consumer electronic products，and China is the most important market of consumer products and the biggest world manufacture center of the consumer products．We launch a reach on audio power amplifier． With the continuous development of science and technology, especially the development of integrated circuit technology, high speed and high power devices have more and more, mobile phones, digital media technology, flat-screen TV, a portable electronic products such as digital product is portable to thin, rapid development, audio power amplifiers will tend to be highly effective, energy-saving and miniaturization. Because mobile devices affected by the battery capacity, thermal, volume restrictions on audio power amplifier requires efficient, energy-saving, low calorific value, small size, ease of integration. Traditional analog audio power amplifier although with high fidelity, but there is a high power consumption, low efficiency and so fatal flaws, and gets very hot, not easy to solve. And class-d amplifiers due to work on or off, as control components of transistor itself lower power consumption, power amplifier is very efficient. Unlike traditional class AB audio power amplifiers, digital class D audio power amplifier