What can affect the LED junction temperature?
There are three things which can affect the junction temperature of LED’s: drive current, thermal path and ambient temperature. In general, the higher the drive current, the greater the heat generated at the junction. Heat must be moved away from the junction in order to maintain expected light output, lifespan and color. The amount of heat that can be removed depends upon the ambient temperature and the design of the thermal path from the junction to the surroundings. Typically the junction temperature should be maintained below 120°C.
