Switching regulator, control method thereof and power-supply device

A method of controlling a switching regulator, configured to convert an Input voltage input to an input terminal into a predetermined constant voltage by switching with at least two elements including a pair of switching elements or a switching element and a rectifying element, and output the converted voltage as an output voltage from an output terminal, comprising:

• a step performed by a comparison unit of the switching regulator of comparing a signal showing an oscillating frequency of the switching regulator with a signal showing a constant frequency;
• and
• a step performed by a driver of the switching regulator of delaying a pulse signal generated by feeding-back a control signal and an output signal of the switching regulator according to the comparison result by the comparison unit with a predetermined time, and switching the input voltage by using the at least two elements based on the pulse signal after the delay,
• wherein the comparison unit includes an oscillation circuit configured to generate the signal showing a constant frequency, and output the signal, a frequency comparison circuit configured to compare the signal showing the oscillating frequency of the switching regulator with the signal showing a constant frequency, and output a signal corresponding to the comparison result, and a comparator configured to compare a proportional voltage proportional to the output voltage or a composite voltage of the proportional voltage and a ripple voltage generated by a ripple generation circuit with a predetermined reference voltage, and output a signal of the comparison result, and
• the driver includes a delay circuit configured to delay the output signal of the comparator based on the signal corresponding to the comparison result with a delay time according to the comparison result, and output the output signal, and a driving circuit configured to generate a control signal to the at least two elements based on the output signal of the delay circuit, and output the signal.