A DC-DC converter control circuit includes an error amplifier, a voltage-to-current conversion circuit, an oscillator circuit, and a pulse frequency modulation (PFM) control circuit. The error amplifier is configured to generate a difference voltage as a difference of an output voltage of the DC-DC converter circuit and a reference voltage. The voltage-to-current conversion circuit configured to convert the difference voltage to a difference current. The oscillator circuit is configured to generate a clock signal at a predetermined frequency for pulse width modulation. The PFM control circuit is configured to disable the oscillator circuit, based on the difference current, for PFM operation.