Overtemperature detection of power semiconductor components

In a circuit arrangement for the generation of a signal when a critical temperature in a power semiconductor component is exceeded, said circuit arrangement using semiconductor components with temperature-dependent current/voltage characteristics, the improvement comprising:

• a bipolar transistor (T 1) in thermal contact with the power semiconductor component and having a temperature dependent leakage current flowing therethrough;
• a current source connected in series with said bipolar transistor, said current source having a current demand which is greater than said leakage current of said bipolar transistor at a given temperature which is less than said critical temperature;
• and
• a threshold element having an input connected to the emitter electrode of said bipolar transistor and an output which provides said signal when said critical temperature is exceeded.