Patent ID: 8736191

Claim:
A method for controlling dimming of LED illumination (brightness) of one or more light emitting diodes (LEDs) where LED illumination is controlled by an LED driver that outputs an LED illumination signal with a duty cycle controlled according to a selectable level of LED illumination (dimming level), the LED dimming control method operable with a dimmer circuit that is operable to output a dimmer selection signal corresponding to the selectable level of LED illumination over a predetermined dimming range of LED illumination, the LED dimming control method comprising: sampling the dimmer selection signal during successive sampling periods and outputting a corresponding LED illumination signal with a duty cycle corresponding to the selectable level of LED illumination; and adjustably filtering the LED illumination signal to control the rate of duty cycle change between consecutive sampling periods according to at least two levels of filtering: a relatively fast filter level in response to a determination that a change between a current duty cycle for a current sampling period and a prior duty cycle for a most-recent prior sampling period exceeds a threshold; and a relatively slow filter level in response to a determination that a change between duty cycles for consecutive sampling periods has not exceeded the threshold for a specified number of sampling periods.