Electret microphone

An electret microphone, comprising:

• a microphone capsule with an output connection,
• a first input connection as an earth connection and a second input connection for providing a supply voltage for the microphone capsule and for leading out a microphone output signal of the microphone capsule;
• and
• a cascode consisting of a first and a second transistor, wherein the output connection of the microphone capsule is provided as input of the cascode,
• wherein the second transistor is configured as a field effect transistor (FET) and a gate connection thereof is connected to the output connection of the microphone capsule,
• wherein a drain connection of the second transistor is coupled to an emitter connection of the first transistor as a bipolar transistor or to a source connection of the first transistor as a FET transistor,
• a third transistor as a self-locking field effect transistor whose third connection is coupled to the second input connection,
• wherein a second connection of the third transistor is coupled via a third capacitor to the earth connection,
• wherein a gate connection is coupled as a first connection of the third transistor via a first resistance to the second input connection,
• wherein the gate connection of the third transistor is coupled to a collector connection of the first transistor as a bipolar transistor or to a drain connection of the first transistor as a FET transistor,
• wherein a fourth resistance is coupled between the drain connection of the second transistor and the second connection of the third transistor.