A 233-MHz 80%-87% efficient four-phase DC-DC converter utilizing air-core inductors on package.
Peter HazuchaGerhard SchromJaehong HahnBradley A. BloechelPaul HackGregory E. DermerSiva G. NarendraDonald GardnerTanay KarnikVivek DeShekhar BorkarPublished in: IEEE J. Solid State Circuits (2005)