带啸叫检测与抑制的音频功率放大器

Audio Power Amplifier with Howling Detection and Suppression

探讨了一种数字移频法啸叫检测与抑制音频功率放大实验测试系统设计方案,用来实现带啸叫检测与抑制音频功率放大.系统以FPGA为控制核心,通过数字移频技术实现啸叫抑制.借助DE2自带的WM8731实现对音频信号的数字采集和输出,利用FPGA内部NCO核实现数字移频,将移频后的数据流通过FIR带通滤波器以保留信号的有效成分.利用OPA134作为前段拾音电路主要放大器件、TPA3112D1作为功率放大器件,利用LCD显示啸叫频率,阐述了啸叫检测与抑制原理、系统软硬件架构以及基于带啸叫检测与抑制的音频功率放大测试系统不同距离检测与抑制啸叫特性.结果表明:该方案能高效实现啸叫检测与抑制,满足带啸叫检测与抑制的音频功率放大实验.

This paper has designed a testing system for an audio power amplifier with howling detection and suppression,which is used to achieve howling detection and suppression audio power amplifier.The system takes FPGA as the control core and realizes howling supperssion through digital frequency. WM8731 of DE2 is used to realize the digital audio signal acquisition and output, using FPGA internal NCO core digital frequency shift, frequency shift after the data flow through the FIR band-pass filter to retain the active ingredients of the signal.As the front pickup using OPA134 amplifier circuit main pieces, TPA3112D1 is a power amplifier part.Using the LCD display whistle frequency;paper expounds the howling detection and suppression of different characteristics from the detection and suppression howl-ing principle, system software and hardware architecture, and with a howling detection and suppression based audio power amplifier test system.The results show that the scheme can efficiently achieve howling detection and suppression, meet audio power amplification experiments with the howling detection and suppression.