A switching regulator that performs voltage regulation using synchronous
rectification in step-up and step-down modes includes input and output
terminals, an inductor, first through fourth transistors, an overcurrent
detection unit, and a control unit. The input terminal receives an input
voltage. The inductor generates an output voltage. The output terminal
provides the output voltage. The first and second transistors perform
switching in the step-down mode. The third and fourth transistors perform
switching in the step-up mode. The overcurrent detection unit detects an
overcurrent condition. The control unit controls operation of the
transistors, causes the first and third transistors to be off and the
second and fourth transistors to be on when the overcurrent condition is
detected in a first state, and causes the first and fourth transistors to
be on and the second and third transistors to be off when the overcurrent
condition is detected in a second state.