MEMORY DEVICE PRE-CHARGING COMMON SOURCE LINE AND OPERATING METHOD OF THE SAME

A method of operating a memory device, the method includes applying a pass voltage to a plurality of word lines during a word line setup period, applying an on-voltage to an unselected ground select line at a first time point during the word line setup period, increasing a voltage of the plurality of word lines by applying a pre-charge voltage to the common source line at a second time point during the word line setup period, applying an off-voltage to the unselected ground select line at a third time point during the word line setup period, and applying a ground voltage to the common source line at a fourth time point during the word line setup period.