说明：  用单片机AT89s52对可编程滤波器芯片MAX262 进行程序控制，可以同时对两路输入信号进行二阶低通、高通、带通、带阻以及全通滤波处理，滤波器的中心频率在15kHz～50kHz 频率范围内实现64 级程控调节，其Q 值在0.5～64 范围实现128 级程控调节。
(In a simple, accurate, reliable, stable and universal principles, use of a hierarchical design to match the idea of interconnection. The characteristics of the system is: through the analog switch to change the feedback resistor value, thus changing the amplifier gain, gain from 10dB to 60dB adjustable step to 10dB. With single-chip programmable filter AT89s52 of MAX262 chip to program, you can at the same time the input signal for two second-order low-pass, high pass, band-pass, band-stop and all-pass filter processing, filter center frequency in 15kHz ~ 50kHz frequency range of 64 to achieve adjustment program, the Q value in the range of 0.5 ~ 64 conditioning program to achieve 128.)