Patent ID: 8981657
Filing Date: 2015-03-17
Classification: H05B

Abstract:
1. A driving circuit for powering a light-emitting diode (LED) light source, said driving circuit comprising: a converter, configured to provide an output voltage to power said light source; said converter comprising a first switch, wherein said first switch is turned on and off alternately according to a driving signal to control a current through said light source; and a controller coupled to said converter and configured to generate said driving signal, wherein said driving signal is a periodic signal having a first state and a second state per time period; wherein said first switch is turned on when said driving signal operates in said first state, and is turned off when said driving signal operates in said second state, wherein said controller modulates a time period of said driving signal and a time duration of said first state, such that a quotient of said time duration squared and said time period is substantially independent of a change of said time period, and said current is substantially independent of said change.