METHOD OF CONTROLLING SWITCHING POWER SUPPLY IN THE CASE OF LIGHT LOAD OR NO LOAD, AND SWITCHING POWER SUPPLY

摘要

PROBLEM TO BE SOLVED: To provide a method of controlling a switching power supply in the case of no load or a light load capable of improving a response speed and reducing an internal loss of a power.;SOLUTION: The method includes: a step of determining whether or not a step-down output voltage Vout satisfies a relation of Vref1≤Vout≤Vref2, where Vref1 represents a first reference voltage and Vref2 represents a second reference voltage; and a step of controlling a high-side FET and a low-side FET so that the relation of Vref1≤Vout≤Vref2 is satisfied, based on a determination result of the determination step. In the control step, when Vout is less than Vref1, the high-side FET is switched so that an amount ΔV1 of an output voltage increased by one conduction of the high-side FET satisfies a relation of ΔV1Vref2-Vref1, and when Vout is greater than Vref2, the low-side FET is switched so that the amount ΔV1 of the output voltage decreased by one conduction of the low-side FET satisfies the relation of ΔV1Vref2-Vref1.;COPYRIGHT: (C)2013,JPO&INPIT