In a data driving apparatus, a DAC converts digital data output from a holding latch into an analog data voltage. An operational amplifier operates as a buffer which outputs the analog data voltage of the DAC to the signal line during a display period and operates as a comparator which compares the voltage of the signal line with the analog data voltage of the DAC during a sensing period. In addition, a sensing controller controls the holding latch to change the data stored in the holding latch according to a comparison value of the comparator.