基于PWM的数字音频播放器设计  

DESIGN OF PWM-BASED DIGITAL AUDIO PLAYER

作　　者：谢可[1] 姚鸿强[1] 

机构地区：[1]江南大学物联网工程学院,江苏无锡214122

出　　处：《计算机应用与软件》2014年第5期328-329,333,共3页Computer Applications and Software

摘　　要：设计采用ARM Cortex_M3处理器内核的LM3S8962芯片为实验平台。对MP3音频文件进行软件解码后,利用PWM控制技术将解码得到的PCM数据转化为一系列幅值相等占空比按PCM数据大小变化的PWM信号,通过H桥式功率放大电路后驱动扬声器发声。大大简化了传统音频解码输出电路的D/A转换和功率放大电路,在保证声音质量的基础上,既节省了成本,又提高了系统的工作性能。经过实验验证,可实现音频文件的正常播放。The design uses LM3S8962 chip in the kernel of ARM Cortex_M3 processor as the experimental platform. After decoding the MP3 audio file with software,the PWM control technology is used to convert PCM data obtained from decoding to a series of PWM signals which have the equal amplitude but their duty ratio vary with the size of PCM data,and then go through the H bridge power amplification circuit to drive the speaker to sound. This has greatly simplified the D / A converter and power amplification circuit of the traditional audio decoding output circuit. More cost has been saved and the system performance has been improved as well on the basis of ensuring the sound quality. Experimental results verify that the normal displaying of the audio file can be achieved.

关 键 词：音频文件 PWM控制 功率放大 

分 类 号：TN912[电子电信—通信与信息系统]