Band pass filter is adopted to remove the high -frequency switching disturbance in node voltage measurements and avoid the time delay of common low pass filter.
针对开关动态对节点电压采样值的干扰，引入带通滤波，滤除高频动态的同时避免了常规低频滤波的延时。
2
With the development of modern electronic technology, frequency synthesizers are required to have wider band, higher resolution, short frequency switching time and lower spurious level.