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PGA450Q1EVM Output waveform

Masaoki Koide
Intellectual 580 points
Other Parts Discussed in Thread: PGA450Q1EVM

Dear Sir,

Our customer is using PGA450Q1EVM and has question about output waveform.

In the Echo Analog Waveform Output from the EVM below, there are unexpected surge noise repeatedly.

Do you have any advise or comments about why the noise occur and where they come from.

 

Regards,

Koide

  • 0
    TI__Mastermind 27940 points
    Hello Koide,

    The noise may actually be a result of the active SPI bus communication coupling onto the return path that feeds into the AFE input. Have they tried running the device in UART or LIN mode to determine if the communication interface is the issue?
  • 0 in reply to Akeem Whitehead
    Intellectual 580 points
    Hello Akeem,

    Thanks so much for the comments. We'll confirm waveform in UART or LIN mode and get back to you.

    Regards,
    Koide
  • 0 in reply to Masaoki Koide
    Intellectual 580 points

    Hello Akeem,

    We've confirmed waveform in LIN and compared waveform in SPI with SDI as well.

    No noise was observed in LIN.

    The noise looks occuring at the same timing with SDI signal, so they were occured by some affects with SDI as you mentioned.

    Do you have any idea to eliminate these noise in SPI?

    Thank you for your advice.

    Regards,

    Koide

  • 0 in reply to Masaoki Koide
    TI__Mastermind 27940 points
    Hello Koide,

    The EVM-GUI combination is continuously performing background operations during the bursting and listening period. If the user is developing their own SPI routines on a custom solution, simply ensure that no SPI activity is performed immediately after issuing the burst command. Wait until the end of the listen period to resume SPI communication.

    The issue you are observing is specific to the EVM-GUI combination, and should not exist in a typical use-case. There is no means of mitigating this noise on the existing EVM-GUI combination. Is the customer able to use UART or LIN instead in their development as a safe-guard?