Patent ID: 8421721

Claim:
A light emitting diode (LED) driving apparatus, comprising: a power conversion circuit, for receiving and converting an input power, so as to generate a direct current (DC) voltage to simultaneously drive a plurality of LED strings arranged in parallel; and a plurality of current regulation chips, each having a single regulation channel and respectively corresponding to the LED strings, wherein an i th current regulation chip is only used for regulating a current flowing through an i th LED string, where i is a positive integer, wherein the i th current regulation chip comprises: a controllable current source, coupled between the i th LED string and a ground, for providing a constant current in response to a dimming signal; and a detection-control unit, coupled to a node between the controllable current source and the i th LED string, for detecting a voltage drop of the controllable current source, and accordingly outputting a control voltage to control a magnitude of the DC voltage generated by the power conversion circuit, so as to regulate-down the voltage drop of the controllable current source to a predetermined voltage drop which makes the controllable current source to be maintained as a constant current source, and then to reduce a power depletion of the controllable current source.