典型的采样数据DSP系统 实际模拟到数字的转换之前，模拟信号一般要经过某些种类的信号调节电路，这些信号要执行像放大、衰减和滤波这样的功能。需要用低通/带通滤波器把不需要的信号从有用带宽中消除掉，并能防止混叠发生-Typical sampled data DSP system, the actual analog-to-digital conversion before the analog signal in general has to go through certain types of signal conditioning circuits, these signals to perform as amplification, attenuation and filtering such functions. Need to use low-pass/band-pass filter the unwanted signal from the useful bandwidth to eliminate out, and to prevent the occurrence of aliasing