A Novel Non-Isolated Full Bridge Topology for VRM Applications

In this paper a new topology is introduced to solve the narrow duty cycle and hard switching problems of the interleaved Buck converter voltage regulator module. The new topology is called the non-isolated full bridge (NFB). In comparison to the interleaved Buck converter, it operates with a significantly wider duty cycle and can achieve zero voltage switching at turn on for the high side MOSFETs. The NFB can significantly reduce the input peak current and transfers a portion of the primary side energy directly to the load thereby reducing the stress on the synchronous rectifiers and filter inductors. Experimental results and analysis demonstrate that the new non-isolated full bridge can significantly improve the performance of a VRM.