• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 30 subscribers
  • Views 543 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Changing Sampling Rate of A2D Converter

Gautam Chebrolu
Prodigy 30 points
Other Parts Discussed in Thread: PCM1864EVM, PCM9211

We are working with the PCM1864EVM and we need to pass a 30kHz signal through it. The signal we get out is heavily filtered, so we think that the board is set at the lowest sampling rate of 48kHz. We were trying to use the PurePath GUI to change the sampling rate to 192kHz through the "Block Diagram" page, but we do not think that the settings were being saved because the output was still degraded. If we change the sampling rate to 192kHz, when we open up the window again it always has switched back to 48kHz. 

We want to send the 30kHz signal through with minimal filtering. What is the best way to change the sampling rate of the board? And are there any filters that can be changed or turned off so that the board will not destroy our 30kHz signal?

  • 0
    TI__Mastermind 27980 points
    Hi Gautam,

    So the GUI defaults the EVM to run its clocks from the PCM9211 on the board, and therefore is in slave mode. What are you using as your clock source, and what mode do you have the EVM in? While in mode 0, you will be outputting audio over the SPDIF port, and can change the sampling rate of the ADC by changing the SPDIF ratio of SCK to LRCK in the EVM tab.

    Justin
  • 0 in reply to Justin Bohr
    Prodigy 30 points

    Justin,

    We did have it in Mode 0 and messed around with changing the ratio of SCK to LRCK, but with no luck. We ended up switching to Mode 1, and this solved our issue! Thanks a lot!

  • 0 in reply to Justin Bohr
    Prodigy 30 points

    Hello,

    We had a follow-up question because our final goal is to use board for a portable application. Everytime we disconnect from USB power and connect to a power supply, we believe that the settings that we changed in PurePath are being erased and the board reverts back to the default settings. Is there any way that we can "burn" the settings into the board? Or is there another board that we should be using with memory?

    Thanks!