Integrated-magnetic gain-enhancement input filter for switchmode power converter circuits

The design and development of a preconverter network is presented, whereby the input voltage range capability of buck or buck-boost-derived DC-to-DC converters can be extended significantly. The proposed integrated-magnetic form of the network uses only three passive circuit components and two diodes and does not require any active switch elements. The preconverter also naturally translates the normally pulsating current drawn by a user power converter into a nonpulsating form, whose AC ripple current magnitude can be reduced to near-zero value by magnetics design