Display device and driving method thereof

A display device comprising:

• a scale factor providing unit which calculates a first scale factor based on input grayscales received during a first frame period;
• a grayscale converter which calculates first output grayscales by applying the first scale factor to first input grayscales received during a second frame period, wherein the second frame period is a frame period immediately next to the first frame period;
• pixels connected to power branch lines commonly connected to a power base line, wherein at least a part of the pixels is configured to display an image based on the first output grayscales;
• a power source which supplies a power voltage to the power base line;
• and
• a current limiting unit which provides a first current limiting signal to the power source and provides a second current limiting signal to the scale factor providing unit when a current of the power base line exceeds a reference value.