US 12,256,472 B2
LED dimming method, dimming controller and system
Wenkai Zhao, Shanghai (CN); Shunfa Zhang, Shanghai (CN); and Weijia Yu, Shanghai (CN)
Assigned to SHANGHAI BRIGHT POWER SEMICONDUCTOR CO., LTD., Shanghai (CN)
Filed by SHANGHAI BRIGHT POWER SEMICONDUCTOR CO., LTD., Shanghai (CN)
Filed on Jun. 28, 2023, as Appl. No. 18/343,382.
Claims priority of application No. 202210854603.2 (CN), filed on Jul. 15, 2022.
Prior Publication US 2024/0023212 A1, Jan. 18, 2024
Int. Cl. H05B 45/10 (2020.01); H05B 45/325 (2020.01); H05B 45/3725 (2020.01)
CPC H05B 45/10 (2020.01) [H05B 45/325 (2020.01); H05B 45/3725 (2020.01)] 18 Claims
OG exemplary drawing
 
1. A light-emitting diode (LED) dimming method for adjusting an output current of an LED by changing a duty cycle of a pulse width modulation (PWM) signal, wherein when the duty cycle of the PWM signal is smaller than a first threshold, the dimming method comprises:
taking every n periods of the PWM signal as one set, and taking an average duty cycle of the n periods of each set as a duty cycle of the PWM signal of the corresponding set; and
taking the set as an output unit, outputting at least two sets of the PWM signal in an order of incrementing or decrementing the average duty cycle by a first predetermined amount ΔP1, thereby changing the duty cycle of the PWM signal,
wherein n is an integer ≥2, 0<ΔP1<0.2%, and wherein at least two periods of the PWM signal in at least one set have different duty cycles.