I have heard that hFE degradation occurs during extended use. What causes hFE degradation, and are there any countermeasures?
A1 hFE degradation may occur due to prolonged use of circuits in which a voltage near or exceeding the reverse bias breakdown voltage (emitter-base voltage VEBO) is repeatedly applied, even momentarily, between the emitter and base of the transistor. The circuit must be designed such that it does not cause reverse bias breakdown between the emitter and the base.