A 0.41mA Quiescent Current, 0.00091% THD+N ClassD Audio Amplifier with Frequency Equalization for PWMResidual-Aliasing Reduction

📋 论文概要

本文提出一种具有频率均衡技术的D类音频放大器，通过在反馈回路中引入频率均衡来抑制PWM残留混叠失真，从而在保持极低静态电流（0.41mA）的同时实现0.00091%的超低THD+N。解决了传统PWM反馈电路中因残留混叠失真导致的THD+N与静态电流之间的权衡问题。

💡 主要创新点

• 提出频率均衡技术，通过在反馈路径中嵌入滤波网络，有效抑制PWM残留混叠失真，无需提高开关频率或增加滤波器阶数。
• 实现了0.41mA的极低静态电流与0.00091%的THD+N，打破了传统设计中功耗与线性度之间的折衷。
• 采用独特的环路补偿结构，在低功耗下保持高保真度，适用于高波峰因数音频信号。

🏷 关键词

📄 原文摘要

a pulse-width-modulation (PWM) modulator and a switching power stage is commonly adopted since it effectively suppresses the power-stage nonlinearity to improve total harmonic distortion plus noise (THD+N). However, unless a higher switching frequency (fSW) or a higher-order loop filter is adopted [2-4], the PWM-residual-aliasing distortion [1] introduced by the feedback loop limits the minimum THD+N. This leads to a tradeoff between THD+N and quiescent current (IQ). Moreover, since typical audio signals have a high crest factor of 10 to 20dB

👥 作者与机构

Shih-Hsiung Chien, Tai-Haur Kuo, Hung-Yi Huang, Hong-Bin Wang, Yi-Zhi Qiu

National Cheng Kung University, Tainan, Taiwan For Class-D audio amplifiers, the closed-loop topology formed by a loop filter,