Triple-hybrid spread-spectrum technique for conducted-noise reduction in DC-DC converters with an FPGA-based implementation

A novel technique for conducted-noise reduction has been proposed in this paper. The proposed technique uses three randomized parameters for generating the switching signals. These parameters are carrier frequency, duty-ratio, and the pulse position. This triple-hybrid spread-spectrum technique has been designed and implemented using field-programmable gate array (FPGA) technology. Moreover, the effect of using the proposed controller on common-mode and differential-mode noise, total conducted-noise, and radiated-noise characteristics of the converter has been experimentally investigated. Furthermore, sweeping of the three randomization parameters has been carried-out for reaching the values which achieve the best conducted-noise spectrum spreading. All the 64 studied cases have been designed, implemented and experimentally investigated. Then, the conducted-noise spectrums have been compared. The experimental results show that using the proposed technique, with the reached randomization parameter values, significantly improves the conducted-noise spectrum and effectively reduces the noise peaks at both high and low frequency ranges. Moreover, the radiated-noise spectrum has been improved.