摘要
为了进一步改善滤波器的频率响应和时延特性,在数字信号和音频信号传输中,整个通带内具有恒定的增益和群延时,使通带内被过滤的信号波形不失真,提出了一种8阶贝塞尔低通滤波器精确设计的方法。硬件电路主要由专用滤波器芯片MAX275、单片机和数字电位器组成。滤波功能由MAX275及其外围16个电阻完成。16个电阻的精确参数值,通过单片机控制数字电位器得到。软件部分采用美国MAXIM公司的专用滤波器设计软件。通过仿真分析、试验测试及实际应用,实现了整个通带内具有恒定的增益和群延时。该滤波器结构简单,易于设计,具有推广价值。
A precise design method of 8-order Bessel low-pass filter was proposed in this paper to further improve the filter＇s frequency response and delay characteristics and avoid the signal waveform distortion when the pass band has constant gain and group delay during the digital signal and audio signal transmission. The hardware circuit is mainly composed by special filter chip MAX275, digital potentiometers and micro control unit（MCU）. Filtering is conducted by MAX275 and 16 resistors outside. Accurate values of the 16 resistors arc obtained through potentiometer control by MCU. The software section adopts special filter design soft- ware of MAXIM Company. A constant gain and group delay within the pass band can be achieved by simulation analysis, experi- mental testing and practical application. The filter with a simple structure is easy to design and promote.
出处
《电子技术应用》
北大核心
2012年第7期68-71,共4页
Application of Electronic Technique
