手持设备中D类功放的设计与应用  

Design and Application of Handsets Class-D Audio Amplifier

作　　者：胡二勐[1] 田晓明[1] 郭德华[1] 

机构地区：[1]东南大学电子工程系,南京210096

出　　处：《电子器件》2007年第1期152-154,共3页Chinese Journal of Electron Devices

摘　　要：传统的模拟功放存在效率低的缺点,不适合手持设备应用.为此介绍了基于脉宽调制技术的D类功率放大器TPA2005的原理和TPA2005在嵌入式系统中的应用.指出了D类功放失真和上掉电瞬时噪声产生的原因,通过在功放前端和后端加入滤波电路的方法降低了功放的pop噪声.并加入了逆变控制电路来减小系统的静态噪音,使功放输出功率为1.2W时失真度THD+N小于1.5%,从而实现了嵌入式音视频系统中D类功放的低噪声设计.Conventional analog Audio Power Amplifier is inefficient and is not suited for handsets. The principle of CLASS--D Audio Power Amplifier TPA2005 based PWM technology and the application of TPA2005 CLASS_D Audio Power Amplifier are instructed. The reasons for pop noise and distortion when the system is powered on or off are pointed. The feasible ways are discussed by appending filters before and after the amplifier. And add the reverse circuit for static noise. Finally, when the output power is 1. 2 W, the THD＋N is less than 1. 5%. The low Pop and static noise in the system are implemented.

关 键 词：手持设备 D类功放 静态噪音 pop噪声 滤波电路 

分 类 号：TN946.7[电子电信—信号与信息处理]