US Patent 8725218 Multimode operation DC-DC converter

Embodiments for at methods, apparatus and systems for operating a voltage regulator are disclosed. One method includes generating, by a switching controller, a switching voltage through controlled closing and opening of a series switch element and a shunt switch element. Further, the method includes generating, by a switchable output filter, a regulated output voltage by filtering the switching voltage, wherein the switchable output filter comprises a plurality of capacitors that are selectively included within the switchable output filter.