Diode recovery characteristics considerations for optimizing EMI performance of continuous mode PFC converters

The design of the boost rectifier diode ratings of a continuous mode boost PFC circuit is usually straight forward but the selection of the recovery characteristics is usually always decided by the final cost and efficiency requirements of the design. This paper explores the effect of diode recovery and it's snap factor characteristics, on the overall EMI and efficiency performance of a continuous mode boost PFC converter. By making extensive measurements and comparing the results of conducted and radiated EMI for three different diode types on a 1200 W prototype operating at about 70 kHz, a systematic design approach is suggested