Patent ID: 9504110
Filing Date: 2016-11-22
CPC Classification: H05B

Claim Text:
1. A driver circuit for driving light emitting diodes (LEDs) comprising: a first interface configured to receive an alternating current (AC) power from an AC power source; a second interface configured to connect to a plurality LED groups; a plurality of current sinks, each current sink of the plurality of current sinks controlling an LED current flowing through a corresponding LED group of the plurality of LED groups; a current level setting block configured to generate a fixed reference voltage; and a third interface configured to receive an adjustable direct current (DC) control voltage input from a control unit, wherein the control unit is external to the driver circuit and connected to the current level setting block via the third interface, and wherein a voltage difference between the adjustable DC control voltage input from the control unit and the fixed reference voltage generated by the current level setting block is used to control an LED current that flows through the plurality of LED groups and adjust brightness of the plurality of LED groups.