Patent ID: 7956586

Claim:
A control method of a step-up/step-down type DC-DC converter including: a first switching element connected between a voltage input terminal and one terminal of an inductance element; a first rectifying element connected between a reference potential and one terminal of the inductance element; a second rectifying element connected between a voltage output terminal and the other terminal of the inductance element; and a second switching element connected between the reference potential and the other terminal of the inductance element, the method comprising: setting either one of a first state and a second state in a first cycle and, in case that the first state is set, switching from the first state to the second state when current of the inductance element reaches a given value in the first cycle; and setting the first state in a second cycle following the first cycle and switching from the first state to a third state when current of the inductance element reaches the given value in the second cycle, wherein in the first state, the first and second switching elements are ON; wherein in the second state, the first and second switching elements are OFF; wherein in the third state, the first switching element is ON and the second switching element is OFF; wherein the first cycle includes a consecutive sequence of the first state and the second state, or includes the second state; and wherein the second cycle includes a consecutive sequence of the first state and the third state.