A system for monitoring a circuit, comprising a device under test, such as a power field effect transistor or capacitor, coupled to a power source and a signal source and configured to generate a power output using the signal source, a current output, a voltage output and an end of life detector coupled to the current output and the voltage output and configured to generate a first impedance as a function of the current output and the voltage output, to compare the first impedance to a second impedance and to generate an indicator if the first impedance exceeds the second impedance.