a DC-DC converter, including a conversion unit configured to convert a battery voltage input to an input terminal of the DC-DC converter into a first voltage, and to output the first voltage to an output terminal of the DC-DC converter, a feedback voltage generation unit configured to generate a feedback voltage by dividing the first voltage, an error amplifier (AMP) configured to supply, to a pulse width modulation (PWM) control circuit, an error signal indicating a voltage difference between the feedback voltage and a reference voltage, the PWM control circuit being configured to control the conversion unit, corresponding to the error signal, thereby changing the first voltage, and a reference voltage supply unit configured to supply the reference voltage to the error AMP, and to change the reference voltage.