Patent ID: 8242765
Filing Date: 2012-08-14
Classification: H02M

Abstract:
1. A switching power supply device comprising: a switching element which turns on and off a first DC voltage; an energy conversion circuit which converts the first DC voltage into a second DC voltage, the first DC voltage being switched by said switching element; a control circuit which outputs a driving signal for controlling an ON operation and an OFF operation of said switching element, using a voltage having an electric potential identical to an electric potential of a connection point between said switching element and said energy conversion circuit as an operation reference voltage; an output voltage detection circuit which detects a voltage signal corresponding to the second DC voltage and outputs a current signal corresponding to the detected voltage signal; and a current detection circuit which detects a current of the current signal output from said output voltage detection circuit, wherein said output voltage detection circuit includes: a rectification circuit which converts the second DC voltage into a voltage signal rectified relative to the operation reference voltage of said control circuit; and a voltage-to-current converter which converts the rectified voltage signal into the current signal corresponding to the rectified voltage signal, and said current detection circuit detects the current of the current signal by sampling the current signal.