LED power supply and EMC compliance

This paper provides theoretical an experimental discussions on constant current drivers for high power LEDs, relative EMI emissions (both conducted and radiated emissions). It is shown the design of a low cost constant current buck converter used to drive a series of high power LEDs. Paying attention to the switching frequency of the converter it is possible to attenuate the conducted and radiated emissions enough to meet the emission limits prescribes by CEI EN 55015 (CEI 110-2) and CEI EN 61000-4-3 (CEI 210-39) regulations, also having a high Power Factor and an improved energy quality.