Patent ID: 7759823
Filing Date: 2010-07-20
Classification: H02J,H03K

Abstract:
1. A switching device for selectively switching the connection between any one of a plurality of voltage sources and a power-supplied device, each of switching paths for connecting each of the plurality of voltage sources and the power-supplied device comprising: an input terminal, to be connected to any one of the voltage sources; a common output terminal, to be connected to the power-supplied device; and a first and a second enhancement type P-channel MOS transistor, the drain electrode of the first enhancement type P-channel MOS transistor and the source electrode of the second enhancement type P-channel MOS transistor being connected to each other; wherein the gate electrode of the first enhancement type P-channel MOS transistor is connected to the output terminal; the gate electrode of the second enhancement type P-channel MOS transistor is connected to the input terminal; the first enhancement type P-channel MOS transistor and the second enhancement type P-channel MOS transistor are connected in series; the output terminal is connected to the gate electrode of the first enhancement type P-channel MOS transistor via a first resistor; and the input terminal is connected to the gate electrode of the second enhancement type P-channel MOS transistor via s second resistor.