Effects of Spread Spectrum on Output Filter of Buck Converter

摘要

Consideration is being given to the use of spread spectrum technology (SST) as the one for noise suppression and the one with coexisting action on the components of output filter of buck converter. The analysis shows that the use of SST produces an additional stress on the output filter components such as power inductor and output capacitor. For both components switching modulation generates extra power loss (as opposed to unmodulated case) which increases with the growth of frequency deviation. During this more energy is dissipated just within frequencies which are below nominal switching frequency, than is saved within frequencies that are higher than the nominal switching frequency. But this effect is not strong; it is possible to compensate it by slight increase of nominal switching frequency and thus to maintain high efficiency of converter in the case of SST usage as well.