A display panel driving apparatus includes a data driver, a gate driver, an extra resistance part through which a constant current passes, and a circuit configured to generate a first gamma voltage, and output a first extra gamma voltage indirectly to the data driver through the extra resistance part. The data driver is configured to generate a data signal based on the first gamma voltage and output the data signal to a data line of a display panel. The gate driver is configured to output a gate signal to a gate line of the display panel.