Active filter, system, chip and electronic equipment

The invention discloses an active filter, a system, a chip and electronic equipment, and the method comprises the steps: receiving a to-be-filtered signal of the active filter through an input end of an RC filtering module, and carrying out the passive filtering of the to-be-filtered signal, so as to obtain a passive filtering signal; the voltage output by the output end of the voltage follower module rises and falls along with the rising and falling of the passive filtering signal so as to obtain a voltage following signal; turning the voltage following module to enable the voltage output by the filtering output end to rise and fall along with the rise and fall of the voltage following signal so as to obtain an active filtering signal; the filtering output end is the output end of the active filter; the positive feedback module is connected between the filtering output end and the RC filtering module, and when the frequency of the signal to be filtered falls into a preset cut-off range, the positive feedback