Patent ID: 7535206

Claim:
A synchronous rectifying type switching regulator control circuit, comprising: a soft start circuit that outputs a soft start signal; a first reference voltage circuit that receives the soft start signal and outputs a first reference voltage; a voltage dividing circuit that divides an output voltage and outputs a divided voltage; an error amplifying circuit that amplifies a difference of the first reference voltage and the divided voltage and outputs an error voltage Verr; an oscillator that outputs a triangular wave; a first comparing circuit that compares the triangular wave with the error voltage Verr and outputs an output pulse Vcomp; a second reference voltage circuit that outputs a second reference voltage; a second comparing circuit that compares the second reference voltage with the error voltage Verr and outputs a voltage ERRcomp; a logic circuit that receives the soft start signal, the output pulse Vcomp, and the voltage ERRcomp and outputs a voltage Vcomp 2 , and that outputs the output pulse Vcomp when the error voltage Verr is higher than the second reference voltage during a soft start period; and a synchronous rectifying circuit that outputs a drive signal for driving a switching element when the logic circuit outputs the output pulse Vcomp to the synchronous rectifying circuit in accordance with the soft start signal and the voltage ERRcomp.