POWER SUPPLY AND BATTERY PACK INCLUDING SAME

The described technology relates to a power supply and a battery pack including the same. In one embodiments, the power supply includes an input terminal configured to receive input power, a regulator configured to reduce a voltage of the input power, and a sensing circuit configured to sense an output voltage of the regulator. The power supply also includes a reference voltage controller configured to receive the input power as driving power and to feedback-control the output voltage of the regulator to correspond to a preset reference voltage, based on the sensed output voltage. The power supply further includes a switch arranged between the input terminal and the reference voltage controller and configured to control the driving power applied to the reference voltage controller.