Patent ID: 8144111

Claim:
A light emitting diode (LED) driving circuit, the driving circuit comprising: a DC/DC converter converting an input DC voltage into an output DC voltage according to a voltage control signal; a light emitting device block including a plurality of LED groups connected in parallel to an output terminal of the DC/DC converter, the plurality of LED groups each including a plurality of light emitting devices connected in series to each other; a current source circuit unit including a plurality of current sources connected between the plurality of LED groups of the light emitting device block, respectively, and a ground; a voltage detection unit detecting the output DC voltage of the DC/DC converter; a minimum voltage detection unit detecting a minimum voltage among a plurality of voltages between the plurality of LED groups and the plurality of current sources, respectively; and a single comparator including a first non-inverting input terminal receiving the voltage detected by the voltage detection unit, a second non-inverting input terminal receiving the minimum voltage detected by the minimum voltage detection unit, and an inverting input terminal receiving a predetermined reference voltage.