US Patent 7928715 Switching regulator

Provided is a switching regulator which is capable of reducing soft start time when being activated, and prolonging battery life. The switching regulator has a configuration in which a clamp circuit for clamping a reference voltage is provided in a soft start circuit, and a predetermined period of time since the switching regulator has been activated is divided into a plurality of segments to increase the reference voltage with different slopes for each of the plurality of segments. At an early stage of the activation, the reference voltage is set to be low for preventing an inrush current from a power source, and thereafter, a rate of increase in reference voltage is gradually increased, to thereby reduce the soft start time.