Patent ID: 8686649

Claim:
A device for driving an LED, comprising: a plurality of LED channels configured to be connected with a power supply unit, include at least one LED, and connected in series; and a current path select circuit configured to select a path of current flowing from an output terminal of the LED channel according to voltage levels of each of the output terminals of the plurality of LED channels, wherein the current path select circuit includes: a first current source configured to control current flowing into a ground from an output terminal of a first LED channel LED 1 of which the input terminal is connected with the power supply unit, in response to a first control signal; a second current source configured to control current flowing into a ground from an output terminal of a second LED channel LED 2 of which the input terminal is connected with the output terminal of the first LED channel LED 1 , in response to a second control signal; an nâˆ’1-th current source configured to control current flowing into the ground from an output terminal of an nâˆ’1-th LED channel LEDnâˆ’1 of which the input terminal is connected with an output terminal of an nâˆ’2-th LED channel LEDnâˆ’2, in response to an nâˆ’1-th (n is a natural number of 4 or more) control signal; an n-th current source configured to provide a path of current flowing into the ground from an output terminal of an n-th LED channel LEDn of which the LEDn is connected with the output terminal of the nâˆ’1-th LED channel LEDnâˆ’1; a first control signal generator configured to compare a voltage level of the output terminal of the second LED channel LED 2 with a predetermined reference voltage to generate the first control signal; a second control signal generator configured to compare a voltage level of an output terminal of the third LED channel LED 3 with the reference voltage to generate the second control signal; and an nâˆ’1-th control signal generator configured to compare the voltage level of the output terminal of the n-th LED channel LEDn with the reference voltage to generate the nâˆ’1-th control signal.