A flat panel display comprising: a substrate; a pixel part having a plurality of sub-pixels formed on the substrate; and a data driver supplying to the pixel part data signals and charge signals containing charge values that correspond to the data signals, each charge signal including a first charge signal and a second charge signal, and the first charge signal being a voltage signal selected from a plurality of preset voltage levels, wherein the second charge signal is a current signal corresponding to the difference between the voltage value corresponding to the first charge signal and the charge value that corresponds to the data signal, wherein the data driver comprises a data output part and a data processing part, wherein the data processing part determines the charge value corresponding to the data signal from the data output part and selects the first charge signal from the preset values and generates the second charge signal corresponding to the difference between the charge value and the first charge signal, wherein the data driver further comprises a switch part, wherein the switch part comprises a first switch connected between the converter and the pixel part to supply the data signals to the pixel part, a second switch connected between the converter and the pixel part to supply the second charge signals to the pixel part, a third switch connected between the converter and a discharge path to discharge the pixel part, and a fourth switch connected between the first charge signal output part and the pixel part to supply the first charge signals to the pixel part, wherein the switch part further comprises a current mirror part connected between the converter, the third switch and the discharge path. a substrate; a pixel part having a plurality of sub-pixels formed on the substrate; and a data driver supplying to the pixel part data signals and charge signals containing charge values that correspond to the data signals, each charge signal including a first charge signal and a second charge signal, and the first charge signal being a voltage signal selected from a plurality of preset voltage levels, wherein the second charge signal is a current signal corresponding to the difference between the voltage value corresponding to the first charge signal and the charge value that corresponds to the data signal, wherein the data driver comprises a data output part and a data processing part, wherein the data processing part determines the charge value corresponding to the data signal from the data output part and selects the first charge signal from the preset values and generates the second charge signal corresponding to the difference between the charge value and the first charge signal, wherein the data driver further comprises a switch part, wherein the switch part comprises a first switch connected between the converter and the pixel part to supply the data signals to the pixel part, a second switch connected between the converter and the pixel part to supply the second charge signals to the pixel part, a third switch connected between the converter and a discharge path to discharge the pixel part, and a fourth switch connected between the first charge signal output part and the pixel part to supply the first charge signals to the pixel part, a first switch connected between the converter and the pixel part to supply the data signals to the pixel part, a second switch connected between the converter and the pixel part to supply the second charge signals to the pixel part, a third switch connected between the converter and a discharge path to discharge the pixel part, and a fourth switch connected between the first charge signal output part and the pixel part to supply the first charge signals to the pixel part, wherein the switch part further comprises a current mirror part connected between the converter, the third switch and the discharge path.