Protective circuit for a semiconductor switch

A circuit arrangement, comprising

• a semiconductor switch having a gate,
• a gate driver controlling the gate, the gate driver comprising
• an electronic switching unit controllable by a driver voltage of the gate driver,
• a switch-on gate resistor connecting the gate to a switch-on potential to switch on the semiconductor switch, and
• a switch-off gate resistor connecting the gate to a switch-off potential to switch off the semiconductor switch, and
• a protective circuit connected to the gate in parallel with the gate driver,
• the protective circuit comprising
• a damp diode;
• a PNP bipolar transistor, comprising an emitter connected to a cathode of the damp diode
• an NPN bipolar transistor comprising a collector connected to a base of the PNP bipolar transistor and a base connected to a collector of the PNP bipolar transistor,
• a first resistor connected in parallel with the base-emitter path of the NPN bipolar transistor,
• a second resistor comprising a first terminal connected to the base of the PNP bipolar transistor,
• a capacitor connected in parallel with a base-emitter path of the PNP bipolar transistor, and
• a third resistor connected either in parallel with the capacitor or with a first terminal of the third resistor connected to the emitter of the PNP bipolar transistor and a second terminal connected to a second terminal of the second resistor.

A circuit arrangement, comprising:

• a semiconductor switch having a gate,
• a gate driver the gate, the gate driver comprising
• an electronic switching unit controllable by a driver voltage of the gate driver,
• a switch-on gate resistor connecting the gate to a switch-on potential to switch on the semiconductor switch, and
• a switch-off gate resistor connecting the gate to a switch-off potential to switch off the semiconductor switch, and
• a protective circuit connected to the gate in parallel with the gate driver,
• the protective circuit comprising
• a clamp diode having an anode connected to the gate,
• a PNP bipolar transistor, comprising an emitter connected to a cathode of the clamp diode
• a NPN bipolar transistor comprising a collector connected to a base of the PNP bipolar transistor and a base connected to a collector of the PNP bipolar transistor,
• a first resistor connected in parallel with the base-emitter path of the NPN bipolar transistor,
• a second resistor comprising a first terminal connected to the base of the PNP bipolar transistor,
• a capacitor connected in parallel with a base-emitter path of the PNP bipolar transistor, and
• a third resistor connected either in parallel with the base-emitter path of the PNP bipolar transistor or with a first terminal of the third resistor connected to the emitter of the PNP bipolar transistor and a second terminal connected to a second terminal of the second resistor.