Patent ID: 9078323
Filing Date: 2015-07-07
Classification: H05B,Y02B

Abstract:
1. A method of driving a light-emitting diode (LED) device, the method comprising: a) generating an absolute value of an AC input voltage; b) generating a driving voltage and a driving current for said LED device through a power switch; c) generating a reference voltage based on said driving current and an expected driving current of said LED device; d) comparing said absolute value of said AC input voltage against a sum of said driving voltage and said reference voltage; e) turning off said power switch when said absolute value of said AC input voltage is greater than said sum of said driving voltage and said reference voltage; and f) turning on said power switch to generate an output current when said absolute value of said AC input voltage is greater than said driving voltage and less than said sum of said driving voltage and said reference voltage.