Patent ID: 6937052
Filing Date: 2005-08-30
Classification: G01R,G11C

Abstract:
1. A current sensing circuit comprising a differential current input stage connected to a differential voltage output stage, the differential current input stage being adapted to receive a reference current input from a current source and a sensor current input from a sensing device and comprising: a first pair of current mirror transistors, each connected to a first common rail, the gates of the first pair of current mirror transistors being connected to each other, and a source or drain of one of the first pair of current mirror transistors being connected to a gate of said one of the first pair of current mirror transistors; a pair of bias transistors, each connected in series to a respective one of the first pair of current mirror transistors, the gates of the pair of bias transistors being biased to saturation; a first pair of nodes, each disposed between one of the pair of first current mirror transistors and a respective one of the pair of bias transistors; and a first switch connected between the first pair of nodes; the current source being connected in series between a second common rail and a respective one of the pair of bias transistors; and the sensing device being connected in series between the second common rail and the other of the pair of bias transistors.