ELECTRONIC CIRCUIT FOR DRIVING PLURAL SERIES CONNECTED LIGHT EMITTING DIODE STRINGS

摘要

PROBLEM TO BE SOLVED: To provide an electronic circuit and a method for driving light emitting diode strings, requiring no minimum select circuit for selecting a lowest voltage appearing at the end of one of a plurality of strings of series connected light emitting diodes.SOLUTION: In an electronic circuit for driving a plurality of light emitting diode strings 14, 16, 18 using a DC-DC converter 12a, input nodes 20a, 22a, 24a or output nodes 20b, 22b, 24b of current regulators 20, 22, 24 are coupled to an end of a respective one of the plurality of light emitting diode strings and pass a respective predetermined current. The electronic circuit also includes a plurality of error amplifiers 78, 80, 82 each of which has an input/output node, is coupled to the input node or the output node of a respective one of the plurality of current regulators, and generates an error signal at a coupling node coupled to the output node.