Power converter, LED driver and control method
AssigneeSilergy Semiconductor Technology (Hangzhou) LTD
InventorsQiukai Huang, Jianxin Wang, Qingliang Zheng
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Abstract
A power converter for an LED drive circuit, can include: a capacitor and an LED load coupled in parallel to receive an output signal of a rectifier circuit; a power switch coupled in series with the LED load, and being configured to control a current path from the rectifier circuit to the LED load; and a control circuit configured to control the power switch to be turned off in accordance with an error between an output current flowing through the LED load and a desired current value to decrease power consumption of the power switch, where the operation of the power switch is controlled to transition between on and off states in each sinusoidal half-wave period.
Claims14
A power converter for a light-emitting diode (LED) drive circuit, the power converter receiving an input voltage, and being configured to drive an LED load, the power converter comprising:
- a) a capacitor and an LED load coupled in parallel to receive said input voltage;
- b) a power switch coupled in series with said LED load, and being configured to control a current path from said input voltage to said LED load;
- and
- c) a control circuit configured to control an operation state of said power switch, such that an input current is generated during a first time period of a half power frequency period in a rising or a falling phase of said input voltage in which a voltage difference between two power terminals of said power switch is less than a predetermined value, in order to decrease power consumption of said power switch, wherein said control circuit is configured to control said power switch to cause a value of said input current during said first time period to be greater than a value of said input current during a second time period of said half power frequency period.
Dependencies are inferred from the claim text.