Patent ID: 8599521
Filing Date: 2013-12-03
Classification: H02M

Abstract:
1. A switching regulator for converting an input power source voltage into a predetermined constant voltage and outputting the predetermined constant voltage as an output voltage, the switching regulator comprising: a switch element configured to perform a switching operation so as to be turned on/off according to a control signal that has been input; an inductor configured to be charged by the power source voltage according to the switching operation of the switch element; a rectification element configured to discharge the inductor when the switch element is turned off and the inductor stops being charged, wherein an input current from the power source voltage is equal to an inductor current of the inductor when the switch element is turned off; a control circuit unit configured to control the switching operation of the switch element with the use of the control signal, so that a first proportional voltage that is proportional to the output voltage becomes equal in value to a generated first reference voltage; and a low voltage malfunction prevention circuit configured to generate a second reference voltage that rises as the power source voltage rises and rises more quickly than the first reference voltage when the power source voltage rises and cause the control circuit unit to forcibly turn off the switch element so that the switch element switches to a cutoff status, wherein when the first reference voltage is lower than the second reference voltage, the low voltage malfunction prevention circuit causes the control circuit unit to forcibly turn off the switch element so that the switch element switches to the cutoff status.