Patent ID: 7224152

Claim:
A DC-DC converter comprising: a converter unit including an output transistor, of which activation and inactivation of the output transistor are controlled in accordance with a control signal, for generating output voltage of the DC-DC converter; and a control unit, connected to the converter unit, for generating the control signal that controls the activation and inactivation of the output transistor, in which the control signal has a duty, in which the control unit changes the duty of the control signal based on output current corresponding to the output voltage, the control unit including; a current detection circuit, connected to the converter unit, for detecting the output current and generating a detection signal; an oscillator for generating a pulse signal; a delay circuit, connected to the oscillator, for delaying the pulse signal and generating a delayed pulse signal, the delay circuit changing the delay time of the pulse signal; and a flip-flop circuit having a set terminal, for receiving the pulse signal of the oscillator, and a reset terminal, for receiving the earlier one of the detection signal of the current detection circuit and the delayed pulse signal, wherein the flip-flop circuit generates the control signal with the duty in accordance with the pulse signal provided to the set terminal and the signal provided to the reset terminal.