The challenges imposed on Voltage Regulator Modules (VRM) become difficult to be achieved with the conventional multiphase buck converter commonly used on PC motherboards. For faster data transfer, a decrease in the output voltage is needed. This decrease causes small duty cycle that is accompanied by critical problems which impairs the efficiency. Therefore, these problems need to be addressed. Transformer-based non-isolated topologies are not new approaches to extend the duty cycle and avoid the associated drawbacks. High leakage, several added components and complicated driving and control schemes are some of the trade-offs to expand the duty cycle. The objective of this work is to present a new dc-dc buck-based topology, which extends the duty cycle with minimum drawbacks by adding two transformers that can be integrated to decrease the size and two switches with zero voltage switching (ZVS). Another issue addressed in this thesis is deriving a small signal model for a two-input two-phase buck converter as an introduction to a new evolving field of multi-input converters.