Patent ID: 8552662

Claim:
A driver for providing variable power to at least one LED array when coupled through a phase-modulating dimmer to an AC power supply, the driver comprising: a filtering and rectifying unit for attenuating electromagnetic interference from/to the AC power supply and converting an AC power from the AC power supply into a DC power output; a switching power unit for receiving the DC power output from the filtering and rectifying unit and providing an output current to the LED array; and a control unit for determining the output current to the LED array in response to a comparison between a dim reference signal representing phase-modulating information of the AC power when the phase angle of the AC power is cut by the phase-modulating dimmer and a feedback signal representing an average value of the output current to the LED array, wherein the control unit comprises a first sampling sub-unit adapted to sample the dim reference signal and cause the dim reference signal to be in a low frequency range, and a second sampling sub-unit adapted to sample the feedback signal and cause the feedback signal to be in a low frequency range.