Side effects evaluation of switching frequency modulation in power converters

The switching frequency modulation applied to power converters as EMI reduction technique has been explored during the last years. However, there is some lack in the evaluation of side effects in the converter performance produced by this technique. In this paper we present an evaluation of these undesired effects by measuring the output voltage ripple. To carry out this work we have used a buck converter with a digital controller that implements switching frequency modulation according to periodic (deterministic) patterns. The interaction between the modulation process and the controller is evaluated. On the other hand, we also present a first comparison between other kind of modulation techniques, such as pulse width and pulse position modulations, pinpointing their potentialities