Backlight unit and display device having the same

A display device comprising:

• a display panel comprising a plurality of pixels;
• a driving circuit which controls the display panel to display an image on the display panel;
• and
• a backlight unit which provides light to the display panel, wherein the backlight unit comprises:
• a power converter which generates a light source driving voltage in response to a voltage control signal;
• a plurality of light emitting diode strings, wherein each of the light emitting diode strings receives the light source driving voltage through a first terminal thereof;
• a plurality of transistors corresponding to the light emitting diode strings, wherein each of the transistors comprises:
• a first electrode connected to a second terminal of a corresponding light emitting diode string;
• a second electrode;
• and
• a control electrode;
• a plurality of pull-down resistors corresponding to the transistors, wherein each of the pull-down resistors comprises:
• a first end connected to the second electrode of a corresponding transistor of the transistors;
• and a second end connected to a ground voltage;
• and
• a controller connected to the control electrode and the second electrode to output a plurality of current control signals to the control electrode of each of the transistors and generate the voltage control signal,
• wherein the controller outputs an over-current detection signal when any one of the current control signals has a pulse width greater than a predetermined reference range.