Optimizing Power Supply for White LEDs used in Illumination Application

Description

The high efficiency, long life time, and energy saving potential of LED lamps have made them emerge as a new illumination lighting source. It has been predicted that LEDs will dominate the general illumination market in ten years. One of the key barriers for LEDs being applied to general illumination is their light output degradation. Heat generated at the p-n junction seems to be a major factor influencing light output degradation. The temperature in the p-n junction can be considered to have a linear relationship with the forward current. Therefore, a proper current regulation strategy is important to alleviate the light output degradation and to maximize the useful life of high power LEDs. Based on (i) understanding the degradation mechanisms, (ii) a new non-intrusive method for junction temperature measurement, and (iii) analyzing and evaluating different current regulation strategies, an optimizing close loop controlled power supply that can alleviate the heat of the p-n junction will be studied and developed.