A power management integrated circuit (PMIC) includes voltage regulators, a conversion circuit, a measurement cycle controller, an oscillator, and a control logic. The voltage regulators generate regulator voltages. The conversion circuit converts analog signals indicating load currents of the voltage regulators to generate digital signals corresponding to the load currents. The measurement cycle controller operates in response to a first clock signal having a first frequency and generates an oscillation enable signal that is activated during a measurement period. The oscillator generates a second clock signal having a second frequency higher than the first frequency in response to the oscillation enable signal. The control logic operates in response to the second clock signal and generates power information, indicating power consumed by the load currents during the measurement period, using the digital signals.