Patent ID: 8344653

Claim:
A light emitting diode (LED) backlight driving system, for driving at least one LED array comprising a plurality of LED strings in parallel, the LED backlight driving system comprising: at least one boost power stage circuit, operable to boost direct current (DC) power signals to output driving voltage to drive the LED array; at least one controller, operable to control the boost power stage circuit; at least one multi-channel constant current driving circuit, operable to control current flowing through the LED array and to output regulating voltage to the controller to regulate the driving voltage output by the boost power stage circuit; at least one voltage dividing circuit, operable to divide the driving voltage to generate feedback voltage to send to the controller, the at least one voltage dividing circuit comprising: a first resistor; a second resistor, connected to the first resistor in series between the boost power stage circuit and the ground; and a third resistor with one end receiving the regulating voltage from the multi-channel constant current driving circuit and another end connected between the first resistor and the second resistor; and an offset voltage generating circuit, operable to generate offset voltage to modify the feedback voltage according to at least one mode selection signal; wherein the controller controls the driving voltage according to the modified feedback voltage and the regulating voltage.