Patent ID: 7710088

Claim:
A switching regulator constituted by a plurality of switching regulator circuits for inputting a predetermined common power supply voltage, and supplying an output voltage to a common external circuit, so as to adjust the output voltage that is applied to the external circuit to be a target voltage, comprising: a first switching regulator circuit which outputs a variable power according to a pulse width modulation pulse to be supplied; a second switching regulator circuit which outputs or stops a constant power according to a control signal to be supplied; an output decision circuit which detects the output voltage to be applied to the external circuit; and a control circuit which adjusts the pulse width modulation pulse to be supplied to the first switching regulator circuit and the control signal to be supplied to the second switching regulator circuit according to a detected voltage supplied from the output decision circuit, so as to control the output voltage to be supplied to the external circuit, wherein the control circuit compares the detected voltage and the target voltage, decreases the variable power of the first switching regulator circuit by a predetermined amount if the detected voltage is higher than the target voltage, increases the variable power of the first switching regulator circuit by the predetermined amount if the detected voltage is lower than the target voltage, increases the variable power of the first switching regulator circuit by an amount greater than the predetermined amount if the detected voltage changes from a status higher than the target voltage to a status lower than the target voltage, and decreases the variable power of the first switching regulator circuit by an amount greater than the predetermined amount if the detected voltage changes from a status lower than the target voltage to a status higher than the target voltage.