Patent ID: 7759982
Filing Date: 2010-07-20
Classification: G01R,H03K

Abstract:
1. A current detection circuit comprising: a first semiconductor switching device including a first terminal with a first fixed potential supplied thereto, a second terminal connected to an other end of a load, a second fixed potential being supplied to one end of said load, and a first current control terminal connected to a control input terminal; a second semiconductor switching device including a third terminal connected to said first terminal, a fourth terminal, and a second current control terminal connected to said first current control terminal; a differential amplifier including a non-inverted input terminal (+) and an inverted input terminal (−); a first voltage clamp device provided on a path between said first terminal and said non-inverted input terminal; a second voltage clamp device provided on a path between said first terminal and said inverted input terminal; a variable resistance device including a fifth terminal connected to said fourth terminal and a sixth terminal connected to an other terminal of a detecting resistor, the second fixed potential being supplied to one end of said detecting resistor, a resistor value of said variable resistance device being controlled by an output value of said differential amplifier; a first MOSFET provided on a path between said second terminal and said non-inverted input terminal; and a second MOSFET provided on a path between said fourth terminal and said inverted input terminal.