Patent ID: 8183824

Claim:
A system for driving at least one light-emitting diode (LED) using power from a power source, the system comprising: means for tracking at least one variation which affects brightness of the at least one LED; means for detecting a level of a source voltage output by the power source; means for providing a plurality of operational modes, wherein each operational mode corresponds to driving the LED with an output voltage that is a respective different multiple of the source voltage output by the power source and, in at least one of the operational modes, the output voltage is higher than the source voltage; means for maintaining an LED current flowing through the LED at a desired value in the plurality of operational modes, the means for maintaining the LED current including an LED driver loop to sink the LED current; and means for generating one or more control signals, in response to the tracking means and the detecting means, for adaptively changing among the plurality of operational modes for driving the at least one LED in order to maintain consistent brightness for the at least one LED.