Patent ID: 8436592

Claim:
A voltage buck-boost switching regulator comprising: a first switching circuit for voltage reducing connected between a voltage input terminal and one terminal of an inductance element; a second switching circuit for voltage boosting connected between another terminal of said inductance element and the voltage output terminal; an error amplifier that compares the output voltage obtained at a voltage output terminal or the output divided voltage obtained by a resistive voltage divider with a prescribed reference voltage, and amplifies the difference between them at a prescribed amplification rate to generate an error voltage; a current sense circuit that detects an inductance current flowing in said inductance element and generates a current sense signal corresponding to said inductance current; a variable sawtooth wave generator that generates a first variable sawtooth wave signal having a first top peak level and a first bottom peak level corresponding to said error voltage and a first slope corresponding to said output voltage, and a second variable sawtooth wave signal having a second top peak level and a second bottom peak level corresponding to said error voltage and a second slope corresponding to the input voltage input at said voltage input terminal; a first switching controller that compares the voltage level of said current sense signal and the voltage level of said first variable sawtooth wave signal, and controls said first switching circuit corresponding to their magnitude relationship; and a second switching controller that compares the voltage level of said current sense signal and the voltage level of said second variable sawtooth wave signal, and controls said second switching circuit corresponding to their magnitude relationship.