【摘要】 为了实现程控滤波的功能,采用状态变量的方法,给出了一种单片机控制的程控滤波器实例。采用两组二阶状态变量滤波器级联,实现了低通、高通、带通输出,并将数模转换器等效为可控电阻,使得截止频率可调。整个电路滤波效果理想,精度高,调试方便,成本低廉。更多还原

【Abstract】 In order to achieve programmable filtering functions,the system uses the state variable approach,giving an example of programmable filter controlled by an SCM.Adopting two cascaded second-order state variable filter it can achieve low pass,high pass,band-pass output,and using the digital to analog converter as the program-controlled equivalent resistance,making the cutoff frequency adjustable.The entire circuit has high accuracy,convenient debugging,and low cost.更多还原