Patent ID: 8502508

Claim:
A switching regulator circuit configured to perform step up and step down operations to convert an input voltage to a predetermined output voltage, the switching regulator circuit comprising: an inductor; and a basic circuit to which the inductor is connected, the basic circuit comprising: a switching circuit to perform switching; a control circuit to control the switching circuit; a first terminal connected to one end of the inductor and the switching circuit, an external load being connectable to the switching circuit through the first terminal; a second terminal connected to the switching circuit and connectable to another external load; and a third terminal connected to the switching circuit, wherein the control circuit is configured to perform a step up operation to boost the input voltage by outputting a boosted output voltage to said another external load connected to the second terminal, by charging the inductor via the first terminal and the third terminal and discharging the inductor via the first terminal and the second terminal, and wherein the control circuit is configured to perform a step down operation to drop the input voltage and output a dropped output voltage to the external load connected through the first terminal, by charging the inductor via the first terminal and the second terminal and discharging the inductor via the first terminal and the third terminal, and wherein the basic circuit further comprises a detection circuit to detect whether the input voltage is applied to an end of the inductor opposite the first terminal or whether the input voltage is applied to the second terminal, the control circuit is configured to perform the step up operation when the detection circuit detects that the input voltage is applied to the end of the inductor opposite the first terminal, and the control circuit is configured to perform the step down operation when the detection circuit detects that the input voltage is applied to the second terminal.