In a method of operating a display apparatus, during a first period in which image data is provided to a data driver, a clock embedded data signal having an output differential voltage (“VOD”) set to a first voltage value is applied to the data driver. The VOD of the clock embedded data signal relates to a voltage difference between a high level and a low level of the clock embedded data signal. During a second period in which the image data is not provided to the data driver, the VOD of the clock embedded data signal applied to the data driver is changed to a second voltage value smaller than the first voltage value.