Patent ID: 8258714
Filing Date: 2012-09-04
Classification: H05B,Y02B

Abstract:
1. An LED controller with phase-shift dimming function, comprising: a power circuit for supplying DC power to multiple LED channels; and an LED phase-shift dimming circuit for receiving an input pulse width modulation (PWM) signal and generating multiple phase-shifted PWM signals with a shifted phase between one another, wherein a turn-ON timing of each of the multiple phase-shifted PWM signals follows a turn-OFF timing of a previous PWM signal which is the input PWM signal or a previous one of the multiple phase-shifted PWM signals, wherein the LED phase-shift dimming circuit includes multiple delay locked loops (DLLs) coupled in series, and each DLL duplicates a PWM signal which it receives to generate the phase-shifted PWM signal with a shifted phase to the received PWM signal.