Ripple Estimation in Commercial Off-the-shelf DC-DC Converters

Due to the lack of information about the internal details of commercial DC-DC converters, modeling techniques that require this information are often not applicable. Instead, blackbox behavioral models can be applied. Previously developed approaches use exclusively the information available in the datasheets to identify the model. In these approaches, the switching mechanism is neglected, and therefore, the voltage ripple is not modeled. In this work, a methodology for estimating the ripple is proposed. For a given topology, the ripple is analyzed and an expression for its amplitude is derived. Then, the parameters of the model are obtained from measurements provided by datasheets or experimental tests. The technique is validated experimentally with two commercial converters. The ripple estimation can be useful at areas such as EMI noise estimation, analysis of the effect of the ripple on radio frequency amplifiers, and stability analysis in cascaded converters.