Patent ID: 7804285

Claim:
A switching regulator converting a voltage input to an input terminal into a predetermined constant voltage and outputting the converted voltage from an output terminal, the switching regulator comprising: a switching transistor configured to perform switching in accordance with an input control signal; an inductor charged with an input voltage by the switching of the switching transistor; a voltage comparator circuit part configured to compare a voltage at a connection of the switching transistor and the inductor and a predetermined voltage, and to generate and output a binary signal indicating a result of the comparison; a phase comparator circuitpart configured to compare a phase of the control signal input to a control electrode of the switching transistor and a phase of the output signal of the voltage comparator circuit part, and to generate and output a signal indicating a result of the comparison; and a control circuit part configured to perform one of a first control and a second control on the switching transistor in accordance with the output signal of the phase comparator circuit part so that the output voltage output from the output terminal is the predetermined constant voltage, the first control being a PWM control and the second control being one of a PFM control and a VFM control, wherein the control circuit part is configured to perform the PWM control in response to the output signal of the phase comparator circuit part indicating that the control signal and the output signal of the voltage comparator circuit part are in phase, and to perform the one of the PFM control and the VFM control in response to the output signal of the phase comparator circuit part indicating that the control signal and the output signal of the voltage comparator circuit part are out of phase, and wherein the phase comparator circuit part is configured to determine that the control signal and the output signal of the voltage comparator circuit part are in phase in response to a difference between the phases thereof being less than a predetermined value.