decrease sensitivity of a MEMS microphone

[HenkMartijn]

Hi!

I like the small MEMS microphones, but they are too sensitive for our application 🙂

Does anybody know if there is a way to create an passive acoustic damper ~20 dB, with good high frequency behaviour (flat response) ?

I would like to decrease the sensitivity and increase the overload point so doeing this electronically is not an option.

[George_T]

Hi @HenkMartijn,

The sensitivity of the microphone depends on the Acoustic Overload Point (AOP). The lowest sensitivity will be for the microphone with the lowest AOP. So from the microphone side the IM69D120 will be having the least sensitivity.

AOP is the point below which total harmonic distortion is less than 10 % and beyond that point microphone performance will be affected. 

Regarding your requirement are you looking for an external arrangement for reducing the sensitivity and increasing the AOP?

Thanks and regards,

George

[HenkMartijn]

Hi George,

Isn't it the other way around? You want to reach an AOP as high as possible, this is only possible if your microphone has a low sensitivity. The IM73A135 is better in that sense. I'm also looking for an analog output. 

So Yes I'm looking for an external arrangement.

/Henk

[George_T · Accepted solution]

Hi @HenkMartijn,

Thanks for the correction. 

The  acoustic specifications of microphone can be understood from the figure below, from the application note.

 

Regarding the passive acoustic damper, I will get back to you soon.

Thanks and regards,

George

[HenkMartijn]

Thanks!

[George_T]

Hi @HenkMartijn,

Sorry for the delay in response.

Could you please elaborate the end application so that we can understand the requirement, better?

The placement of microphone and external damper is very critical.

Please let me know whether the discussion needs to be moved to a private channel.

Thanks and regards,

George

[HenkMartijn]

Hi George, 

Yes it would be nice if we could move this conversation to a private channel.

Thanks!