Digital charge balance controller with an auxiliary circuit for superior unloading transient performance of Buck converters

In this paper, a digital charge balance controller is presented which is capable of controlling a Buck converter and an auxiliary circuit to achieve an excellent unloading transient response. The auxiliary circuit significantly reduces the voltage overshoot caused by an unloading transient while the digital charge balance controller reduces the settling time of the converter. The controller is capable of implementing load-line regulation and yields a smooth transition from one loading condition to another. Simulation and experimental verification is performed and demonstrates significant transient improvement over previously-proposed solutions.