Power voltage generator and display device having the same

A display device comprising:

• a display panel including a gate line, a data line, and a pixel connected to the gate line and the data line and configured to display an image based on input image data;
• a gate driver configured to output a gate signal to the gate line;
• a data driver configured to output a data voltage to the data line;
• and
• a power voltage generator configured to apply a power voltage to the pixel,
• wherein the power voltage generator comprises:
• a booster configured to boost an input voltage to an output voltage based on an on-off operation of a switch,
• a voltage sensor configured to generate a sensing voltage by sensing the output voltage;
• a constant voltage controller configured to generate a first switching signal to control the switch by comparing the sensing voltage with a reference voltage,
• a constant current controller connected to the switch to receive an electrode signal from the switch and configured to generate a gain based on a ratio of the electrode signal of the switch and a target signal by comparing the electrode signal of the switch with the target signal, and
• a gain operator connected to the constant voltage controller to receive an output from the constant voltage controller and the constant current controller to receive the gain from the constant current controller, and configured to generate a second switching signal by multiplying the gain to the first switching signal, and
• wherein the output voltage is the power voltage.

A power voltage generator comprising:

• a booster connected between an input voltage node and an output voltage node, the booster including a switch which includes a source electrode connected to a ground and a gate electrode:
• a voltage sensor connected to an output node and outputting a sensing voltage;
• a first OP AMP which includes a first input electrode receiving the sensing voltage and a second input electrode receiving a reference voltage to output a first switching signal;
• a second OP AMP which includes a first input electrode receiving a target duty ratio signal and a second input electrode connected to the switch;
• and
• a gain operator connected between the switch and the first OP AMP, and the switch and the second OP AMP, the gain operator receiving the first switching signal from the first OP AMP and a gain from the second OP AMP.