THD改善的D类音频功放(英文)  

Class D Audio Amplifier with Improved THD Performance

作　　者：黄武康[1] 袁国顺[1] 周长胜[2] 林福坚[2] 

机构地区：[1]中国科学院微电子研究所,北京100029 [2]中国科学院嘉兴微电子与系统工程中心,浙江嘉兴314006

出　　处：《半导体技术》2009年第6期594-597,共4页Semiconductor Technology

基　　金：Major Scientific and Technical Special Fund of Science and Technology Department of Zhejiang Province of China(2006C14036)

摘　　要：提出了一种双环反馈拓扑结构的D类音频功放。通过对基于脉冲宽度调制的D类功放反馈系统的分析,指出环路参数对总谐波失真THD和电源抑制比PSRR等性能有着重要的影响,讨论了如何通过参数优化来改善一阶单环反馈D类功放的THD指标。在此基础上提出了一种双环反馈拓扑结构,通过数学分析显示该二阶闭环系统的THD指标能得到更进一步地改善。测试结果显示,双环结构D类功放的THD较单环得到了7倍的改善。A Class D audio amplifier with dual-loop feedback topology was presented. Analytical modeling of the closed-loop Class D amplifier based on pulse-width modulation （PWM） indicates that the loop parameters have important influence on THD and PSRR performance. It is shown how the THD of a 1^st-order single feedback loop Class D amplifier can be improved by parameter optimization. Based on the former analysis, a dual-loop feedback topology was then proposed, and mathematical analysis shows the THD can be further improved by means of 2nO-order closed-loop system. Experimental results show that the THD of the derived dual-loop Class D amplifier is improved by 7 times than the single-loop one.

关 键 词：D类放大器 脉冲宽度调制 总谐波失真 双环反馈 电源抑制比 

分 类 号：TN402[电子电信—微电子学与固体电子学]