US Patent 7330046 Circuits and methods for failure prediction of parallel MOSFETs

Power conversion circuits often consist of several MOSFETs operating in parallel. Due to thermal cycling and mechanical operations. MOSFETs or the respective electric connections of the MOSFETs may fail. For certain implementations, a diagnosis circuit for a plurality of parallel MOSFETs predicts or determines a possible failure on the basis of at least one of temperatures of the MOSFETs or gate voltages of the MOSFETs. In some applications, the MOSFETs are monitored to facilitate early determination of failures of the MOSFETs.