Liquid crystal display and method of controlling common voltage thereof

A liquid crystal display comprising:

• a liquid crystal panel having a plurality of pixels;
• a lookup table which stores information about a plurality of digital common voltages, each of the plurality of digital common voltages corresponding to at least one gray value;
• a timing controller which analyzes gray characteristics of image signals to be displayed on the liquid crystal panel and which selects only one of the digital common voltages based on an analysis result;
• and
• a common voltage generator which generates only one analog common voltage in response to the one digital common voltage selected by the timing controller and which supplies the analog common voltage to the liquid crystal panel,
• wherein the timing controller determines a representative gray ratio using a histogram analysis result obtained based on each gray value of a red signal, a green signal and a blue signal constituting the image signal, and selects the digital common voltage corresponding to the representative gray ratio from the lookup table.