Analysis of the beat frequency oscillation in voltage regulators

In the voltage regulator (VR) applications, the load transient frequency varies in a very wide range from several kHz to several MHz. When the load transient frequency approaches to the switching frequency of VR, there is a low frequency oscillation in the system, which is the beat frequency oscillation between the load transient frequency and the switching frequency of VR. And this may hurt the system. In this paper, utilizing the multi-frequency modeling technique, this beat frequency oscillation is modeled and analyzed. The compensator design to reduce the beat frequency oscillation is suggested and verified with the hardware.