Patent ID: 7679351

Claim:
A power supply apparatus comprising: a voltage generation unit generating a driving voltage for driving a load; a first feedback path feeding back a voltage according to a voltage at one end of the load; a second feedback path feeding back a voltage according to a voltage at the other end of the load; and a control circuit controlling the voltage generation unit so that one of a first feedback voltage and a second feedback voltage fed back by the first feedback path and the second feedback path, respectively is closer to a predetermined reference voltage; wherein the control circuit includes an error amplifier amplifying an error between one of the first feedback voltage and the second feedback voltage and the reference voltage, and adjusts the driving voltage so that the error is closer to zero, and the error amplifier includes two input differential pairs, the reference voltage and the first feedback voltage being input to one of the two input differential pairs, and the reference voltage and the second feedback voltage being input to other input differential pair.