Optimal Buck Converter Output Filter Design for Point-of-Load Applications

This paper presents a novel method to design the output filter of low-voltage/high-current buck dc-dc switching regulators. The method is based on the concept of acceptability boundary curves (ABCs). ABCs are the curves bounding the regions in the space of parameters, including commercial components which ensure an acceptable output voltage ripple and a load-transient surge based on design specifications. ABCs help in quickly finding tradeoff design solutions, as well as in a better understanding of the functional correlations among power components. Examples regarding buck converters for point-of-load applications are discussed to highlight the flexibility and reliability of the ABC-based design method. Experimental measurements confirm the analytical results and numerical predictions.