Patent ID: 7851946
Filing Date: 2010-12-14
Classification: H02M

Abstract:
1. A switching power supply apparatus which generates and outputs two different voltages of a first and second output voltages from one input voltage, comprising: a flying capacitor; a first output capacitor which is provided between a first output terminal, from which said first output voltage is output, and a fixed potential terminal; a second output capacitor which is provided between a second output terminal, from which said second output voltage is output, and a fixed potential terminal; a first switch provided between one end of said flying capacitor and an input terminal to which said input voltage is applied; a second switch provided between the other end of said flying capacitor and said input terminal; a third switch provided between said one end of said flying capacitor and a fixed potential terminal; a fourth switch provided between said other end of said flying capacitor and a fixed potential terminal; a fifth switch provided between said one end of said flying capacitor and said first output terminal; a sixth switch provided between said other end of said flying capacitor and said second output terminal; and a control unit which performs on-off control of said first through said sixth switches, wherein said control unit divides time into: a first charging period in which said first switch and said fourth switch are turned on, and said flying capacitor is charged by said input voltage; a second charging period in which said second switch and said fifth switch are turned on, and a voltage approximately two times said input voltage is output from said first output terminal; and a third charging period in which said third switch and said sixth switch are turned on, and a voltage which is obtained by inverting said input voltage, is output from said second output terminal, and said charging periods are repeated.