低成本播放大功率高保真数字语音的信号方法及快速验证方法  

Signal processing and fast verification methods for playback of high-Power high-fidelity digital audio with a low-cost embedded microprocessor

作　　者：朱旭东[1] 

机构地区：[1]无锡工艺职业技术学院,江苏宜兴214221

出　　处：《电子设计工程》2016年第7期125-128,共4页Electronic Design Engineering

摘　　要：通过一系列信号处理,仅利用低成本单片机和Class-D功率放大器就可以播放大功率高保真语音信号。通过采样率转换、内插、噪声整形和均衡,单片机的脉冲宽度调制(PWM)端口不仅可以输出高保真语音信号,而且可以补偿喇叭和电路的频响曲线。仿真PWM端口作用于低通滤波器后的输出然后生成.WAV文件。利用媒体播放器等软件播放这个.WAV文件可在设计实际电路前检验信号处理后的语音的质量。利用单片机开发板、耳机和简单的电阻电容滤波也可检验信号处理对语音质量的影响。最后基于ATSAM3系列单片机的电路板达到了接近CD的音质并在没有附加散热器的情况下在50 V供电时可驱动4欧姆喇叭。This paper discusses playback of high-power high-fidelity digital audio only with a low-cost embedded microprocessor and a class-D amplifier. By utilizing some signal processing techniques such as sample-rate-conversion, interpolation,noise-shaping and equalization, the pulse-width-modulation ports not only can output HI-FI audio, but also can compensate unequal frequency response of the speaker and the circuits. A.WAV file is generated by sampling the simulated output of PWM after a low-pass filter. The audio quality after the signal processing can be easily verified by playback the.WAV file with Mediaplayer. The audio quality can also be verified with an emulator board, an earphone, and a simple RC low-pass filter. A demo board based on Atmel ATSAM3 can playback with CD audio quality. The board can drive a 4-ohm speaker with 50 V DC supply.

关 键 词：单片机 class-D功放 采样率转换 插值 噪声整形 均衡补偿 

分 类 号：TN29[电子电信—物理电子学]