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数字功率放大电路工作原理与功率损耗实例分析
作者:韩跃平 李瑞红 毕满清 王黎明 来源:《现代电子技术》2015年第20期
摘 要: 当前国内高校的“电子线路”课程无论是从教材编写还是课堂讲授中的功率放大电路仍然以模拟功放为主,对数字功放讲述甚少,而现实中电子产品尤其是笔记本电脑、手机等便携式电子产品大量采用了低功耗高集成度的数字开关门电路芯片,造成大学生课堂学习与电子技术发展实际的脱节。在此结合数字集成开关门(CMOS)电路的发展,详细分析了D类功率放大电路的工作原理;理想状态下,D类功率放大电路的理论效率可达到100%,远高于AB类模拟功率放大电路的78.5%。推导了D类功率放大电路CMOS反相器的功率损耗与芯片工作的时钟频率、栅极集总电容值以及芯片所需的供电电压的平方成正比,并以当前主流的集成度达8 000万个门电路(2 inch2上108个门)的IBM笔记本电脑的CPU芯片为实际案例进行了总功耗分析。实践表明,将数字功率放大电路引入大学生课堂教学,可以贴近实际,增强感性认识,提高课堂教学质量。
关键词: 数字功率放大器; 工作原理; 功率损耗; 实例分析
中图分类号: TN722?34 文献标识码: A 文章编号: 1004?373X(2015)20?0107?03 Instance analysis for working principle and power loss of digital power amplification circuit
HAN Yueping, LI Ruihong, BI Manqing, WANG Liming
(State Center of Electrical and Electronic Demonstration Experiment, North University of China, Taiyuan 030051, China)
Abstract: While the power amplification circuit of “electronic circuit” course in the aspects of textbook compilation or classroom teaching is still taking analog circuit as the main content in colleges, and the digital power amplification circuit is described extremely less, the digital switching gate circuit with low power consumption and high integration is adopted massively in electronic products (especially in laptops and mobile phones) in reality, which separates
classroom learning of students from development of electronic technology. In combination with the development of CMOS circuit, the working principle of D?class power amplification circuit is analyzed in detail. The theoretical efficiency of D?class power amplification circuit can reach 100% in ideal condition, and is higher than AB?class analog power amplification circuit of 78.5%. The power loss of CMOS inverter of D?class power amplification circuit is proportional to the working