LED DRIVER

摘要

An LED driver can include: a rectifier circuit receiving an AC voltage, and providing a DC output voltage; an LED array having N LED units having at least one LED coupled between first and second output terminals of the DC output voltage; (N−1) groups of switches, each having two switches coupled in series between the first and second output terminals, where a common node of the two switches is coupled to a common node between two adjacent LED units, where the operation of the two switches of each group is complementary such that when the switch is on, the LED unit coupled in parallel with the switch is out of operation; and an LED configuration control circuit that controls the on/off states of switches to control operation of the LED units.

主权项

1. A light-emitting diode (LED) driver, comprising:
a) a rectifier circuit having an input for receiving an AC voltage, and an output for providing a DC output voltage by rectifying said AC voltage; b) an LED array comprising N LED units having at least one LED coupled between a first output terminal and a second output terminal of said DC output voltage; c) (N−1) groups of switches, each group of switches comprising two switches coupled in series between said first and second output terminals of said DC output voltage, wherein a common node of said two switches of each group is coupled to a common node between two adjacent LED units, and wherein the operation of said two switches of each group is complementary such that when said switch is on, said LED unit coupled in parallel with said switch is out of operation; and d) an LED configuration control circuit configured to control the on and off states of switches to correspondingly control operation of said LED units in accordance with a value of said DC output voltage and a current requirement for a current flowing through said LED units.