In this paper many spread-spectrum schemes, several of which are new, have been designed and implemented for conducted-noise reduction in DC-DC converters. A fieldprogrammable gate array (FPGA) has made substantial improvements in price and performance throughout the past few years. The implementation of the schemes has been accomplished by using FPGA-based controller. A breadboard circuit has been built-up for investigating the effect of all the proposed schemes on conducted-noise spectrum in DC-DC converters. Furthermore, a comparative study has been carried-out to reach the most efficient scheme in spreading the conducted-noise spectrum. Experimental results show that randomizing each of carrier frequency, duty-ratio, and the pulse position parameters significantly improves the conducted-noise spectrum and effectively reduces the noise peaks at both high and low frequency ranges.