Patent ID: 7522432
Filing Date: 2009-04-21
Classification: H02M,Y02B

Abstract:
1. A switching regulator that performs voltage regulation using synchronous rectification to provide a given constant voltage in step-up and step-down modes, the switching regulator comprising: an input terminal configured to receive an input voltage; an inductor configured to generate an output voltage based on the input voltage; an output terminal configured to provide the output voltage generated by the inductor; a first transistor configured to perform switching to charge the inductor in the step-down mode; a second transistor configured to perform switching to discharge the inductor in the step-down mode; a third transistor configured to perform switching to charge the inductor in the step-up mode; a fourth transistor configured to perform switching to discharge the inductor in the step-up mode; an overcurrent detection unit configured to detect an overcurrent condition during the voltage regulation; and a control unit configured to control operation of the first through fourth transistors to regulate the output voltage to the given constant voltage, and to cause the first transistor to be off, the second transistor to be on, the third transistor to be off, and the fourth transistor to be on when the overcurrent detection unit detects the overcurrent condition in a first state, and cause the first transistor to be on, the second transistor to be off, the third transistor to be off, and the fourth transistor to be on when the overcurrent detection unit detects the overcurrent condition in a second state, the overcurrent condition indicating that a current at the output terminal exceeds a given current level, the first state indicating that the input voltage is below the output voltage, the second state indicating that the input voltage is above the output voltage.