Double-hybrid spread-spectrum technique for conducted-EMI reduction in DC-DC switching regulators with FPGA-based controller

The purpose of this paper is to present a novel technique for conducted-noise reduction in de-de switching regulators. In order to effectively spread the conducted-noise frequency spectrum and, at the same time, attain a satisfactory voltage regulation, two parameters (carrier frequency and pulse position) have been randomized, and the third parameter (duty ratio) has been controlled by a digital compensator. Furthermore, the effect of using the proposed controller on common-mode, differential-mode, and total conducted-noise characteristics of the converter has been experimentally investigated. The converter's performance with using the proposed technique has been experimentally investigated. It is assumed that the implementation technology is a field programmable gate array (FPGA) which is becoming increasingly adopted in industrial electronic applications.