Monitoring Transistor Degradation in Power Inverters Through Pole Shifts

In a power inverter configuration with pull-up and pull-down transistors, ringing that occurs on the high-to-low and low-to-high transitions can be used to track aging or degradation of the transistors and potentially predict failures. Changes in a transistor's equivalent resistance and capacitance can affect the frequency and damping factor of the characteristic ringing detected on the inverter's output. In this paper, the matrix pencil method is used to locate the poles associated with this ringing, and detect shifts in position that indicate transistor degradation.