Dimming control method, dimming control circuit and power converter thereof
AssigneeSilergy Semiconductor Technology (Hangzhou) LTD
InventorsHongbin Lai, Jianxin Wang
Life of this patent
Estimating the term…
Abstract
A method of controlling a power convertor to perform dimming control for a light-emitting diode (LED) load, can include: adjusting a length of a switching period of the power converter in accordance with a dimming signal; and controlling the power converter to generate a drive current corresponding to the dimming signal.
Claims18
A method of controlling a power convertor to perform diming control for a light-emitting diode (LED) load, the method comprising:
- a) adjusting a length of a switching period of the power converter in accordance with a dimming signal;
- b) controlling the power converter to generate a drive current corresponding to the dimming signal;
- and
- c) adjusting a switching state of a power stage circuit of the power converter in accordance with a first compensation signal that characterizes an error between a sampling signal of the drive current and a current reference signal during a first time interval, wherein the switching period comprises the first time interval and a second time interval, and a length of the first time interval is determined by a maximum set value of the dimming signal.
A dimming control circuit for controlling a power converter to perform diming control for a light-emitting diode (LED) load, the dimming control circuit comprising:
- a) a first control circuit configured to control a switching state of a power stage circuit of the power converter in accordance with a first compensation signal that characterizes an error between a current reference signal and a sampling signal of a drive current during a first time interval of a switching period;
- b) wherein a length of the switching period of the power converter is adjusted in accordance with a dimming signal;
- c) wherein the power converter is controlled to generate the drive current corresponding to the dimming signal;
- d) wherein when a set value of the dimming signal is decreased, the length of the switching period is controlled to be increased correspondingly to decrease the drive current;
- and
- e) wherein a length of the first time interval is controlled by a lock signal, and the length of the first time interval is determined in accordance with a maximum set value of the dimming signal.
Dependencies are inferred from the claim text.