Patent ID: 7276861

Claim:
A system for driving one or plurality of LEDs, comprising: an energy source; a power converter for transferring electrical power from said energy source to said LEDs in a form of a controlled output current and providing said LEDs brightness regulation, said power converter being constructed as a switching converter, comprising an inductor, a rectifier, a power switch, operating in a dual phase cycle, having an on phase, when said power switch is closed, exciting said inductor by an input voltage, and an off phase when said power switch is open; a peak current sensor through said power switch; a regulator, controlling said dual phase cycle at a constant frequency and coupled to said power converter and receiving feedback signals from at least one of an electrical, thermal or optical sensor for sensing said LEDs performance and comprising: (i) an LEDs current sensor; (ii) an integrator with a reset, coupled to said LEDs current sensor for generating an integrated signal over said off phase of said cycle of said LED's current signal; (iii) a comparator for comparing said integrated LEDs current signal to a reference signal; (iv) a digital logic, sampling said comparator and resetting said integrator each cycle and generating a control signal to regulate said LED's current; (v) a D/A converter coupled to said digital logic to convert said control signal from digital to analog form; (vi) a current peak comparator, connected to said peak current sensor to compare a peak current to a set point equal to said control signal and turning off the said power switch, when said peak current in the said power switch reaches a level of said set point; an oscillator, coupled to said digital logic; and a buffer to drive said power switch.