DC-DC converter and semiconductor IC for cable voltage drop compensation

A semiconductor integrated circuit that controls a power supply constituting a DC-DC converter that converts a DC input voltage supplied from a DC power supply and outputs a DC output voltage with a different potential, by turning on and off a switching element connected between a voltage input terminal and an external terminal to which one terminal of an inductor is connected, and rectifying a current flowing through the inductor, the semiconductor integrated circuit comprising:

• a control circuit that controls the switching element in accordance with a potential difference between a feedback voltage proportional to the DC output voltage and a predetermined reference voltage;
• a current supply circuit that causes a predetermined current to flow;
• a path switch that outputs the current of the current supply circuit toward a voltage output terminal;
• a voltage correction circuit that corrects the reference voltage or the feedback voltage;
• and an external information input terminal through which an information signal from outside is input, wherein the voltage correction circuit is configured to determine a voltage correction amount, based on the information signal input through the external information input terminal from a load side when the current of the current supply circuit is output, and correct the reference voltage or the feedback voltage.

A power supply device converting a DC input voltage supplied from a DC power supply and outputting a DC voltage with a different potential, the power supply device comprising:

• a control circuit that controls a switching element or a transistor for voltage control connected between a voltage input terminal and a voltage output terminal, in accordance with a potential difference between a feedback voltage proportional to an output voltage and a predetermined reference voltage;
• a current supply circuit that causes a predetermined current to flow;
• and
• a voltage correction circuit that corrects the reference voltage or the feedback voltage,
• wherein the voltage correction circuit is configured to determine a voltage correction amount, based on information about a resistance on a load side input from outside when a current of the current supply circuit is output, and correct the reference voltage or the feedback voltage.