Flicker Percent (FP)
Flicker Percent (FP) is the simplest measure of ripple based on the measurement of maximum and minimum ripple amplitudes. If the waveform is changed (while maintaining the values of ripple amplitudes), such as from sine to rectangular or filling of a rectangular waveform, the value of the ripple factor will remain the same. The range of possible values is from 0% (in the absence of ripple) to 100%. IEEE 1789-2015 recommendations suggest flicker percent values <0.08× the ripple frequency (8% for a ripple frequency of 100 Hz). This is a low-risk level (low-risk level). The second, higher criterion implies that the ripple level will be at the so-called NOEL (no observable effect level) and will not exceed 0.0333× ripple frequency (3% for 100 Hz ripple frequency).
maximum - the maximum amplitude of the signal.
minimum - the minimum amplitude of the signal