A power switching circuit and a method for controlling the same are disclosed herein. The power switching circuit includes a frequency control circuit, a pulse modulation circuit, and a switching convertor. The frequency control circuit receives a first reference signal driving a load, from a timing controller, and generates a second reference signal based on the first reference signal. The pulse modulation circuit generates a pulse control signal by performing pulse width modulation (PWM) or pulse frequency modulation (PFM) on the second reference signal. The switching convertor generates the voltage of output power by switching a switching element connected to the output power, in response to the pulse control signal. The pulse control signal is synchronized with the first reference signal driving the load.