Dc-dc converter and display device including the same

A direct current-to-direct current converter comprising:

• a boost converter which outputs a first power voltage in a normal mode or in a power saving mode based on a first inductor current generated therein, wherein when the booster converter is in the power saving mode, the booster converter operates in a second driving manner, in which a magnitude of the first inductor current is continuously changed based on a first pulse width modulation signal having a first driving frequency, and when the booster converter is in the power saving mode, the booster converter operates in a second driving manner in which the magnitude of the first inductor current is not changed during a first discontinuous period based on the first pulse width modulation signal having a second driving frequency;
• a first inverting converter which outputs a second power voltage based on a second inductor current generated therein in the normal mode or in the power saving mode, wherein when the first inverting converter is in the power saving mode, the first inverting converter operates in a third driving manner or in a pulse frequency modulation manner which lowers a frequency, and when the first inverting convert is in the normal mode, the first inverting converter operates in one of the first driving manner, the second driving manner and the third driving manner, which is determined based on a magnitude of a load of a display panel connected thereto, wherein when the first inverting converts operates in the third driving manner, a magnitude of the second inductor current is not changed during a second discontinuous period based on a second pulse frequency modulation signal;
• and
• a second inverting converter which does not operate in the power saving mode, wherein the second inverting converter outputs the second power voltage in the first driving manner or the second driving manner when the load of the display panel exceeds a preset reference load in the normal mode,
• wherein the second discontinuous period is longer than the first discontinuous period.

A display device comprising:

• a display panel including a plurality of pixels, wherein the display panel displays an image in one of a normal mode and a power saving mode;
• a data driver which provides a data signal to the display panel;
• and
• a direct current-to-direct current converter which supplies a first power voltage and a second power voltage lower than the first power voltage to the display panel, and supplies a source driving voltage to the data driver,
• wherein the direct current-to-direct current converter includes:
• a first converter which outputs the first power voltage based on a first inductor current generated by alternately turning on a plurality of transistors therein, wherein the first converter operates in a first driving manner in the normal mode, and operates in a second driving manner in the power saving mode;
• and
• a second converter which outputs the second power voltage based on a second inductor current generated by alternately turning on a plurality of transistors therein, wherein the second converter operates in a third driving manner in the power saving mode, and a magnitude of the second power voltage in the power saving mode is different from a magnitude of the second power voltage in the normal mode.