摘要
设计一种音频功率放大系统。采用Ti的TPA3112D1芯片实现功率放大,采用移频算法抑制声反馈环路的啸叫,基于DSP芯片TMS320C5509实现该算法,其通过单片机来设定音频放大器的最大功率和与之匹配的系统放大倍数。设计啸叫频率与放大器输出功率的测量电路。实际硬件电路测试结果表明,在20mV输入信号下,输出功率有效可调范围为50mW-5W;在1.5W-5W输出功率范围内,系统效率均高于80%,最高达到90%;通过缩短话筒和喇叭之间的距离诱发啸叫现象,DSP移频算法介入后,啸叫现象被有效抑制,音频信号本身基本不受影响。
An audio power amplification system was designed. TPA3112D1 based on Ti chip was used as power amplifier, and a frequency shifting method based on DSP chip TMS320C5509 was used to suppress the howling in the loop of acoustic feedback. The maximum output power and the system magnification were programmed by controlling MCU in the system. Moreover, the measuring circuits of howling frequency and output power were designed. The test results show that the output power can be ad- justed from 50 mW to 5 W with a 20 mV input signal, the system efficiency is higher than 80% under the output power range of 1.5 W-5 W, and the maximum efficiency is up to 90%. The howling phenomenon can be triggered by shorting the distance be- tween microphone and loudspeaker. In this case, the howling phenomenon can be suppressed effectively and the original audio signal is barely affected using the frequency shifting method.
出处
《计算机工程与设计》
北大核心
2015年第12期3235-3240,共6页
Computer Engineering and Design
基金
陕西省自然科学基础研究计划基金项目(2014JQ8338)
西安市科技计划基金项目(CXY1342(6))
中央高校基本科研业务费基金项目(2013G1321041
2013G3322010)
关键词
啸叫检测
啸叫抑制
音频功率放大
DSP
移频
howling detection
howling suppression
audio power amplification
DSP
frequency shift
