Microphone module

Patent metadata

Field	Value
Publication number	US-10595133-B2
Application number	US-201916293081-A
Country	US
Kind code	B2
Filing date	Mar 5, 2019
Priority date	Mar 16, 2018
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

A microphone module includes a first MEMS microphone and a second MEMS microphone, wherein the first MEMS microphone includes a first modulator, and wherein the second MEMS microphone includes a second modulator. For the purpose of noise reduction, a defined offset can be applied to an input of the first modulator or of the second modulator. Alternatively, for the purpose of noise reduction, the first modulator and the second modulator can be operated with different modulation frequencies.

First claim

What is claimed is:

1. A microphone module, comprising:
a first MEMS (Micro-Electro-Mechanical Systems) microphone, wherein the first MEMS microphone comprises a first modulator;
a second MEMS microphone, wherein the second MEMS microphone comprises a second modulator; and
an offset generator, wherein the offset generator is directly connected to an input of the first modulator or of the second modulator, and wherein the offset generator is configured to apply a defined offset to the input of the first modulator or of the second modulator.

2. The microphone module as claimed in claim 1 ,
wherein the offset generator is configured to adapt the defined offset.

3. The microphone module as claimed in claim 1 ,
wherein the offset generator is configured to adapt the defined offset in such a way that limit cycles of the first modulator and of the second modulator differ by at least 5 kHz.

4. The microphone module as claimed in claim 1 ,
wherein the defined offset is −60 dBFS or more.

5. The microphone module as claimed in claim 1 ,
wherein the first modulator and the second modulator comprise 1-bit modulators.

6. The microphone module as claimed in claim 1 ,
wherein outputs of the first modulator and of the second modulator are connected to a same data line.

7. The microphone module as claimed in claim 1 ,
wherein the first MEMS microphone and the second MEMS microphone are clocked with a same clock signal.

8. The microphone module as claimed in claim 7 ,
wherein the first modulator and the second modulator are clocked with different edges of the same clock signal.

9. The microphone module as claimed in claim 1 ,
wherein the first modulator and the second modulator comprise digital modulators.

10. The microphone module as claimed in claim 1 ,
wherein the first modulator and the second modulator comprise analog-to-digital converters, and
wherein the defined offset comprises an analog DC value.

11. The microphone module as claimed in claim 1 ,
wherein the first MEMS microphone and the second MEMS microphone are switchable in each case between a first operating state and a second operating state, wherein the first MEMS microphone and the second MEMS microphone are switched into different operating states,
wherein the defined offset is applied to the input of the first modulator if the first MEMS microphone is switched into the first operating state, wherein the defined offset is applied to the input of the second modulator if the second MEMS microphone is switched into the first operating state, and
wherein the first MEMS microphone and the second MEMS microphone are switched into the respective operating state by a control signal present at the respective MEMS microphone or by a control value present at the respective MEMS microphone.

12. The microphone module as claimed in claim 11 ,
wherein the first MEMS microphone and the second MEMS microphone are allocated to different channels of a multi-channel application by the different operating states.

13. The microphone module as claimed in claim 1 ,
wherein the offset generator comprises a first offset generator connected to the input of the first modulator, wherein the first offset generator is configured to apply a defined first offset to the input of the first modulator, and
wherein the microphone module comprises a second offset generator connected to the input of the second modulator, wherein the second offset generator is configured to apply a defined second offset to the input of the second modulator.

14. The microphone module as claimed in claim 13 ,
wherein the first MEMS microphone and the second MEMS microphone are switchable in each case between a first operating state and a second operating state,
wherein the first offset generator is configured to apply the defined first offset to the input of the first modulator only if the first MEMS microphone is switched into the first operating state,
wherein the second offset generator is configured to apply the defined second offset to the input of the second modulator only if the second MEMS microphone is switched into the first operating state, and
wherein the first MEMS microphone and the second MEMS microphone are switched into different operating states.

15. The microphone module as claimed in claim 14 ,
wherein the first MEMS microphone and the second MEMS microphone are switched into the respective operating state by a control signal present at the respective MEMS microphone or by a control value present at the respective MEMS microphone.

16. The microphone module as claimed in claim 13 ,
wherein the first offset generator and the second offset generator are configured to apply different defined offsets to the respective inputs of the first modulator and of the second modulator.

17. The microphone module as claimed in claim 1 ,
wherein the first MEMS microphone and the second MEMS microphone are switchable in each case between a first operating state and a second operating state, wherein the first MEMS microphone and the second MEMS microphone are switched into different operating states,
wherein the offset generator comprises a first offset generator connected to the input of the first modulator, wherein the first offset generator is configured to apply a defined first offset to the input of the first modulator if the first MEMS microphone is switched into the first operating state, wherein the first offset generator is configured to apply a defined second offset to the input of the first modulator if the first MEMS microphone is switched into the second operating state,
wherein the microphone module comprises a second offset generator connected to the input of the second modulator, wherein the second offset generator is configured to apply the defined first offset to the input of the second modulator if the second MEMS microphone is switched into the first operating state, wherein the second offset generator is configured to apply the defined second offset to the input of the second modulator if the second MEMS microphone is switched into the second operating state,
wherein the defined first offset and the defined second offset are different, and
wherein the first MEMS microphone and the second MEMS microphone are switched into the respective operating state by a control signal present at the respective MEMS microphone or by a control value present at the respective MEMS microphone.

18. The microphone module as claimed in claim 17 ,
wherein the defined first offset and the defined second offset are different than zero.

19. The microphone module as claimed in claim 17 ,
wherein the first MEMS microphone and the second MEMS microphone are allocated to different channels of a multi-channel application by the different operating states.

20. The microphone module as claimed in claim 1 ,
wherein the first MEMS microphone comprises a first offset compensator connected to the input of the first modulator, wherein the first offset compensator is configured to reduce an analog offset generated by the microphone module or by the first MEMS microphone itself at the input of the first modulator, and
wherein the second MEMS microphone comprises a second offset compensator connected to the input of the second modulator, wherein the second offset compensator is configured to reduce an analog offset generated by the microphone module or by the second MEMS microphone itself at the input of the second modulator.

21. A method for operating a microphone m

Assignees

• Infineon Technologies Ag

Inventors

• Straeussnigg Dietmar
• Bach Elmar
• De Milleri Niccolo
• Sant Luca
• Wiesbauer Andreas

Classifications

• H04R2201/003

  Mems transducers or their use · CPC title

• H04R19/005

  using semiconductor materials · CPC title

• H04R3/00 Primary

  Circuits for transducers (arrangements for producing a reverberation or echo sound G10K15/08; amplifiers H03F) · CPC title

• H04R19/04 Primary

  Microphones (H04R19/01 takes precedence) · CPC title