ADAU1372 ADC Polarity

Hello Wei Cheow,

You are correct that the datasheet is exactly reversed from what the part actually does. The PGA does invert the signal but the ADC also inverts the signals so that the results when using the PGA is no polarity inversion. However, if you bypass the PGA then you will get a polarity inversion in the ADC.

Thanks for bringing this to our attention. I will put in to make a change to the datasheet.

Dave T

Hello Wei Cheow,

You are correct that the datasheet is exactly reversed from what the part actually does. The PGA does invert the signal but the ADC also inverts the signals so that the results when using the PGA is no polarity inversion. However, if you bypass the PGA then you will get a polarity inversion in the ADC.

Thanks for bringing this to our attention. I will put in to make a change to the datasheet.

Dave T

Hi,

I also encountered the similar issue on the ADAU1772.

ADAU1772 and ADAU1372, they have a lot in common except Fast DSP core, I understand.
Does the ADAU1772's ADC also inverts the signals even if written as following?

              ADAU1772 data sheet (rev.C)
              Page 33 Signal Polarity
              The ADCs are noninverting

I found below.
If the ADAU1772's ADC also invert the signals, the issue could occurs, I think.

              Sign inversion ADAU1772
              ez.analog.com/.../sign-inversion-adau-1772

Hello Euglena,

Yes, the parts are very similar so you would see the same thing on the 1772.

Dave T

Hi Dave,

Thanks for your quick reply.

I clearly understand. Based on it, I would like to investigate my issue further.