Patent ID: 7714517
Filing Date: 2010-05-11
Classification: H05B

Abstract:
1. A current feedback circuit for use in a light emitting diode (LED) driver with current sink control comprising a plurality of current feedback units, wherein each of the plurality of current feedback units comprises: a. an input; b. a first output; c. a second output; d. a first reference line for receiving a first supply voltage; e. a second reference line for receiving a second supply voltage; f. a ground terminal for connecting to the ground of the LED driver; g. an operational amplifier (op-amp) having a positive input, a negative input, an output, a first power supply input, and a second power supply input, wherein the first power supply input is electrically coupled to the first reference line, the second power supply input is electrically coupled to the second reference line, and the output is electrically coupled to the second output; h. a first resistor having a first terminal and a second terminal, wherein the first terminal is electrically coupled to the input, and the second terminal is electrically coupled to the first output; i. a second resistor having a first terminal and a second terminal, wherein the first terminal is electrically coupled to the first terminal of the first resistor and the second terminal is electrically coupled to the positive input of the op-amp; j. a third resistor having a first terminal and a second terminal, wherein the first terminal is electrically coupled to the second terminal of the first resistor and the second terminal is electrically coupled to the negative input of the op-amp; k. a fourth resistor having a first terminal and a second terminal, wherein the first terminal is electrically coupled to the negative input of the op-amp and the second terminal is electrically coupled to the output of the op-amp and the second output; and l. a fifth resistor having a first terminal and a second terminal, wherein the first terminal is electrically coupled to the positive input of the op-amp, and the second terminal is electrically coupled to the ground terminal.