Patent ID: 7504783

Claim:
A circuit for controlling a current through an LED, comprising: a regulator for providing said current to said LED; an LED voltage monitoring circuit for monitoring a voltage drop across said LED and providing a voltage reading signal based on said voltage drop; a data converter logic circuit coupled with said regulator and said LED voltage monitoring circuit, wherein said data converter logic circuit is operable to control said regulator to adjust said current based on said signal; an LED current monitoring circuit for monitoring said current through said LED and providing a current reading signal based on said current; a first sample-and-hold circuit coupled with said LED voltage monitoring circuit and said data converter logic circuit, said first sample-and-hold circuit for capturing and providing a first instantaneous value of said voltage reading signal; and a second sample-and-hold circuit coupled with said LED current monitoring circuit and said data converter logic circuit, said first sample-and-hold circuit for capturing and providing a second instantaneous value of said current reading signal, wherein said data converter logic circuit is coupled to receive said first and second captured instantaneous values and operable to control said regulator based thereon.