Study of High Frequency Input Interference for Buck Converter

摘要

Applying the ideal analog signal sampling-recovery model, the high frequency input noise of Buck converter has been analyzed and a new type of noise, called as beat frequency noise, has been first revealed in this paper. The main contributions are as the followings: (1) Some high frequency noise can be shifted to the lower frequency — beat frequency, which could not filter out by original converter; (2) A more accurate model has been proposed to predict the output beat frequency noise; (3) A novel method to reduce the beat frequency noise has been put forward by adding a new pre-filter.