• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 80 subscribers
  • Views 242 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TMS320F28066: F28066 ADC sample signal error

Sammi Shang
Expert 4450 points
Part Number: TMS320F28066

Dear team,

The ADC sampling result of F28066 is not match with the normal signal, I have attached the waveform. The signal comes from hall sensor. Would you kindly give some suggestion?

Thanks.

Best regards,

Sammi

  • 0
    TI__Guru 62975 points

    Sammi,

    Can you describe the problem in terms of device-level behavior?  We are not able to remotely diagnose an application-level issue on a system that we know very little about using only a picture.

    For example: A buffered signal with a 1.5V level is driven on to pin ADCINB3 with an expected conversion value of 1862 LSBs using internal reference mode.  The actual conversion value is 1303 LSBs instead of 1862 LSBs.  This happens across all ACQPS values.  ADCINB4 works as expected.  All issues from the Errata have been managed as recommended.

    -Tommy

  • 0 in reply to tlee
    TI__Expert 4450 points

    Hi Tommy,

    Many thanks for your response. I will confirm more information with customer.

    Except that, customer mentioned that they use F28066 with main OSC at 90MHz, they see an document of F2803X that said high OSC will make ADC has bigger error. So customer want to know what frequency need for ADC?

    Thanks.

    Best regards,

    Sammi

  • 0 in reply to Sammi Shang
    TI__Guru 62975 points

    Sammi,

    The maximum ADC clock frequency is specified in the datasheet as 45-MHz:

    -Tommy