Patent ID: 7830131

Claim:
A control circuit for a switching regulator having a switching transistor comprising: a pulse modulator which generates a modulated pulse signal having a duty ratio adjusted such that the output voltage of said switching regulator matches a predetermined reference voltage; a minimum pulse signal generating circuit which generates a minimum pulse signal which is output synchronously with the modulated pulse signal, and which has a predetermined minimum duty ratio; a corrected pulse signal generating circuit which receives the modulated pulse signal and the minimum pulse signal and outputs a corrected pulse signal such that the corrected pulse signal has a level that corresponds to the modulated pulse signal when the duty ratio of the modulated pulse signal is larger than the minimum duty ratio and has a level that turns off the switching transistor when the duty ratio of the modulated pulse signal is smaller than the minimum duty ratio, a driver circuit which drives said switching transistor according to the corrected pulse signal output from said corrected pulse signal generating circuit; and a stop signal generating circuit which generates a stop signal having a first predetermined level when the duty ratio of the modulated pulse signal is smaller than the minimum duty ratio; a release signal generating circuit configured to generate, when the duty ratio of the pulse signal determined according to the output voltage exceeds the minimum duty ratio, a release signal is output at a predetermined second level, wherein, when the stop signal is in the first predetermined level, at least an oscillator used for pulse modulation is stopped; and wherein, when the release signal transits to the predetermined second level, said stop signal generating circuit switches the stop signal to the level that is complementary to the first predetermined level.