A power voltage generator includes a booster, a voltage sensor, a constant voltage controller and a constant current controller. The booster is configured to boost an input voltage to an output voltage based on an on-off operation of a switch. The voltage sensor is configured to generate a sensing voltage by sensing the output voltage. The constant voltage controller is configured to generate a first switching signal to control the switch by comparing the sensing voltage with a reference voltage. The constant current controller is configured to generate a gain based on a ratio of an electrode signal of the switch and a target signal by comparing the electrode signal of the switch with the target signal.