LED controllers, drivers and lighting circuits

摘要

A controller for controlling a plurality of LED lighting strings is disclosed, the controller comprising, for each of the plurality of LED lighting strings: a frequency modulator configured to modulate a baseline frequency to generate a time-vary modulated frequency, wherein the frequency modulator is configured to modulate the baseline frequency by a jitter superposed on a regular repeating pattern which varies more slowly than the jitter, to result in the modulated frequency; and a modulated PWM signal generator configured to generate a modulated PWM signal having the modulated frequency and a predetermined duty cycle; wherein the regular repeating patterns for the PWM signals are spaced apart in phase. Associated drivers, LED lighting circuits and methods are also disclosed.

主权项

1. A controller for controlling a plurality of LED lighting strings,
the controller comprising, for each of the plurality of LED lighting strings: a frequency modulator configured to modulate a baseline frequency to generate a time-varying modulated frequency, wherein the frequency modulator is configured to modulate the baseline frequency by a jitter superposed on a regular repeating pattern which varies more slowly than the jitter, to result in the modulated frequency; and a modulated PWM signal generator configured to generate a modulated PWM signal having the modulated frequency and a predetermined duty cycle; wherein the regular repeating patterns for the PWM signals are spaced apart in phase.