Microphone and method of operating a microphone
View Patent ↗A microphone and a method for operating a Microphone are disclosed. In an embodiment the microphone includes a transducer and a mode controller. The microphone has a normal operating mode (M O ) and a collapse mode (M 1 ). The mode controller switches to the collapse mode (M 1 ) when an output signal of the transducer reaches or exceeds a predefined threshold value and switches to the normal operating mode (M O ) when the output signal reaches or falls below a predefined further threshold value (S 1 ).
1. A microphone comprising:
a transducer; and
a mode controller for switching between a normal operating mode (M O ) and a collapse mode (M 1 ),
wherein the mode controller is configured to monitor an output signal of the transducer and switches to the collapse mode (M 1 ) when the output signal of the transducer reaches or exceeds a predefined first threshold value (S O ), and switches to the normal operating mode (M O ) when and only when the output signal (S) reaches or falls below a predefined second threshold value (S 1 ).
2. The microphone of claim 1 , further comprising a voltage supply for supplying the transducer with a bias voltage, wherein when the microphone switches to the collapse mode (M 1 ) the bias voltage is decreased.
3. The microphone of claim 1 , further comprising a voltage supply for supplying the transducer with a bias voltage, wherein when the microphone switches to the collapse mode (M 1 ) the bias voltage is maintained.
4. The microphone of claim 1 , wherein, when the microphone switches from the collapse mode (M 1 ) to the normal operating mode (M O ), a bias voltage is first decreased and then increased.
5. The microphone of claim 1 , wherein the microphone is adapted to switch from the collapse mode (M 1 ) to the normal operating mode (M O ) only if the output signal has remained equal to or below the second threshold value (S 1 ) at least during a predefined amount of time.
6. The microphone of claim 5 , wherein the predefined amount of time is longer than 400 ms.
7. The microphone of claim 1 , wherein the first threshold value (S O ) is higher than the second threshold value (S 1 ).
8. The microphone of claim 1 , wherein the first threshold value (S O ) is in a range between 120 and 140 dB SPL.
9. The microphone of claim 8 , wherein the second threshold value (S 1 ) is in a range between 100 and 130 dB SPL.
10. The microphone of claim 1 , wherein, in the collapse mode (M 1 ), a sensitivity of the microphone is smaller than a sensitivity if the microphone in the normal operating mode (M O ).
11. The microphone of claim 1 , further comprising an amplifier and a gain controller for adjusting a gain of the amplifier.
12. The microphone of claim 11 , wherein a sensitivity loss of the transducer in the collapse mode (M 1 ) is compensated by the amplifier.
13. The microphone of claim 11 , further comprising a digital converter, wherein the gain controller is adapted to adjust a gain of the digital converter.
14. The microphone of claim 11 , further comprising a pre-amplifier, wherein the gain controller is adapted to adjust the gain of at least one of the pre-amplifier and the amplifier.
15. A method for operating a microphone, the method comprising:
operating the microphone in a normal operating mode (M O );
monitoring an output signal of a transducer;
switching into a collapse mode (M 1 ) when the output signal of the transducer reaches or exceeds a predefined first threshold value (S O ); and
switching into a normal operating mode (M O ) when and only when the output signal reaches or drops below a predefined second threshold value (S 1 ).