• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 82 subscribers
  • Views 506 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.

TMS320F280039C: ADC Internal reference select, 2.5v or 3.3v?

Zane Wei
Intellectual 1835 points
Part Number: TMS320F280039C


Hi Team, 

We want to know is which one has better performance when 280039C uses the internal 2.5V reference or the 3.3V reference?

How much difference will there be in performance?

Best Regards, 

Zane

  • 0
    TI__Genius 11081 points

    Hello Zane,

    The 2.5V reference will give slightly better dynamic performance/SNR. This is because the 3.3V reference is actually 1.65V internally and so the signal has to be halved when performing the conversion, so the SNR is impacted as a result. These numbers should be provided in the device data sheet.

    Best regards,
    Ibukun

  • 0 in reply to Ibukun Olumuyiwa
    TI__Intellectual 1835 points

    Hi Ibukun,

    Thanks for your help!

    If SYSCLK from INTOSC and use internal VREFHI for ADC reference voltage. Does the 2.5 reference will give slightly better dynamic performance SNR? 

    Best Regards,

    Zane

  • +1 in reply to Zane Wei
    TI__Genius 11081 points

    Zane,

    In theory internal 2.5V should still be slightly better than internal 3.3V with INTOSC. The 3.3V mode effectively reduces the signal amplitude relative to the noise floor so we should see some kind of impact to SNR. However, we do not have this difference quantified.

    Best regards,
    Ibukun