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Simple PDM to analog conversion

Dear Experts,

To use MEMS microphones as replacement for ECM capsules I search for a simple PDM to analog signal solution. It should be linear as possible and provide a high quality analog signal output. Power amplification is not necessary. Amplification of the analog signal to -3dBV can be done using a single OP-Amp.
Using ADAU7002 + ADAU1701 looks too oversized for me. Furthermore the space is restricted.  Best will be a single chip which do the Clock generation ( 2.4Mhz ) and direct conversion to analog singal.

Any solution available or suggestions?

Thanks a lot for your support.

Best regards

  • Hello Karsten,

    If you are looking for a small solution then you should look at the ADAU1777. It is a small wafer level BGA package. It is capable of taking in four PDM microphones, amplifying them, and filtering, then sending them out to two DACs. it is less than 4mm square. 

    We have some other choices but this seems to be the simplest and smallest solution. The ADAU1761 can do this as well but it needs a system controller to boot it up and it is larger. The ADAU1777 can selfboot from an external EEPROM. 

    Dave T

  • Hello Dave,

    Sorry for the delayed answer, I was ill the last days..

    The ADAU1777 looks nice for our project. So I try to get the EVAL board to check the performance.
    Thanks a lot and... take care in this times...