An adaptive frequency hopping technique for conducted-noise reduction in dc-dc converters

This paper introduces a novel technique for conducted-noise reduction in dc-dc converters. The converter is operated in variable frequency modulation regime. To avoid the “bad” switching frequencies□which cause tuning with the converter parasitic elements resonant frequencies and increase the noise peaks□these bad frequencies have been determined and removed from the hop-set frequencies. Furthermore, the effect of using the proposed controller on the conducted-noise characteristics of the converter has been experimentally investigated using an FPGA-based controller. Experimental results show that the conducted-noise spectrum has been significantly improved and the noise level has been effectively reduced.