Analysis of IC op-amp power-supply current sensing

The current characteristics in IC op-amp power-supply current sensing circuits are thoroughly investigated. It is shown that there exists non-ideal currents in op-amp power-supply leads which were formerly considered to be zero. These currents become very large at high frequencies and introduce the main source of errors in these circuits. The equations of the non-ideal currents are given in the paper and based on these, an improved op-amp power-supply current sensing circuit can be obtained.<<ETX>>