ripple noise

A composite value of a small AC voltage, which appears superimposed on the DC voltage as ripple, and high-frequency noise in rectifying and smoothing circuits of power supplies. It consists of remaining AC components that could not be removed by the low-pass filter in the rectifying and smoothing circuit, combined with high-frequency noise components other than the input sine wave. Like ripple, it is represented by one cycle from one waveform peak to the next.