Need to know phase response PDM filters for noise cancellation,

[simmania]

Hi,

We want to use microphones connected to the PDM inputs in a noise cancellation application.
To be able to do correct noise calculation we need to know the phase characteristics of the decimation filters.

Where can we find this information?

[kerryzhou]

Hi @simmania ,

   I already talk your case internally.

   Our internal side need some information from your side:

1.Customer product information.

2. Product use environment

3. microphone array 

Please help to share the related information, as our internal side need to know it.

We have the Voiceseeker/Conversa library, AFE algrothm beamforming can help you do the noise cancellation directly, but it is not free to use, more information, please check this nxp.com web page:

https://www.nxp.com/design/software/embedded-software/voiceseeker-audio-front-end:VOICESEEKER

https://www.nxp.com/design/software/embedded-software/conversa-voice-suite:CONVERSA-VOICE-SUITE

Wish it helps you!

Please help to share the above information to me, thanks.

Best Regards,

kerry 

[kerryzhou]

Hi @simmania ,  

   Please tell me which RT chip you are using now?

  Then I can help you to check the details.

   Best Regards,

Kerry

[simmania]

We will start with the MIMXRT1176DVMAA (Evaluation Kit).

Will it be the same for all RT1170 devices?

[kerryzhou]

Hi @simmania ,

   You can use MIMXRT1176DVMAA which is the MIMXRT1170-EVK board, that's ok, this RT1170 chip is the most functional chip, if this works, then you also can make other RT117X works.

Wish it helps you!

Best Regards,

Kerry

[simmania]

So then can you give me information about the phase response of the decimation filters?

We want to use the microphones in a new noise cancellation method. For this we need to know the phase response of the filters to be able to generate the correct anti sound signals.

[kerryzhou]

Hi @simmania ,

   Thanks for your information, I already help you check internally.

   Any updated information, I will let you know, please keep patient, thanks.

Best Regards,

Kerry