Patent ID: 8217633
Filing Date: 2012-07-10
Classification: H02M

Abstract:
1. A switching regulator comprising: a step-down circuit configured to output a stepped-down voltage lower than an input voltage; a step-up circuit configured to output a stepped-up voltage higher than the input voltage; and a control unit comprising a voltage detector configured to detect an output voltage, the control unit being configured to prohibit step-up operation of the step-up circuit while allowing step-down operation of the step-down circuit until the output voltage rises to a first voltage, said first voltage being lower than the input voltage, wherein in a case that the output voltage rises to the first voltage, the control unit allows the step-down operation of the step-down circuit and the step-up operation of the step-up circuit while the output voltage is (i) higher than a second voltage that is lower than the first voltage and (ii) lower than the input voltage, wherein the step-down circuit comprises: wherein the control unit turns the step-down switching transistor off when the voltage drops across the step-down switching transistor to a voltage below a predetermined value, and the control unit releases an off state of the step-down switching transistor cyclically or every predetermined number of cycles.