Patent ID: 7705483

Claim:
A control circuit for a DC-DC converter which provides a plurality of output voltages, the control circuit comprising: an error amplifier which includes: a first polarity input terminal at which a voltage according to a first output voltage of the plurality of output voltages is input; a second polarity first input terminal at which a reference voltage for setting a target value for the first output voltage is input; and a second polarity second input terminal at which a voltage according to a second output voltage being output from another DC-DC converter is input, wherein the error amplifier amplifies an error between: (i) lower one of voltages between the voltage input at the second polarity first input terminal and the voltage input at the second polarity second input terminal; and (ii) the voltage input at the first polarity input terminal, wherein the control circuit controls the voltage according to the first output voltage so as to keep a relation between the voltage according to the first output voltage and the voltage according to the second output voltage based on the error.