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TLV320AIC3256EVM-U: How to select the proper sample rate?

Part Number: TLV320AIC3256EVM-U

When using the TLV320AIC3256EVM-U, I have meet some problems.

With this topology in PPS GDE, some noise occurs.

The noise is always existing, no mater the I2S signal or analog signal is given or not.

I changed the sample rates, and the noise maybe disappear.

Some experimental result as follow.

CurrenRate      Board sampling rate        Is there noise?

Rate44              44100Hz                              yes

Rate48              48000Hz                              yes

Rate88              48000Hz                              no

Rate176            48000Hz                              no

Rate192            48000Hz                              no

 

I’m puzzled at the board sampling rate. What is the relationship between the SamleRate(or the CurrenRate) and the board sampling rate?

 

In my product, I’ll use I2S with 44.1kHz.

I used the base_main_Rate44_pps_driver.h code to my product, and the same noise occurred. So is base_main_Rate192_pps_driver.h.

How can I do to sovle the noise?

And how to select the proper sample rate?

Thanks!

  • Hi,

    Welcome to E2E, Thanks for your interest in our products!.

    I looked at the process flow and see a potential problem which might be causing the noise issue. When creating a new process flow in PurePath Studio (PPS), the first step is to select an appropriate framework, which will determine the filters used and hence,  the compatible sampling rates. In your application, Framework AIC3256App2x1x is used, which actually is recommended for 176.4KHz and 192KHz sampling rates. If this framework is used with lower sampling rates, it is very likely to hear undesired noise. I would recommend you to change the framework according to your desired sampling rate (AIC3256App8x4x would be the recommended for 44.1KHz). For more information, please right-click over the framework and open the help file.

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer

  • Diego,

    Thanks you for your answering.

    Using your solution, the noise disappeared on the EVM. But it didn't work on my production.

    I have posted anther question.

    https://e2e.ti.com/support/data_converters/audio_converters/f/64/t/690061

    Hope to get your suggestion and thanks again.