Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

  • State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 32 subscribers
  • Views 150 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.

DP83TG720R-Q1: DP83TG720RWRHATQ1

Mehdi Noroozi
Prodigy 60 points
Part Number: DP83TG720R-Q1

Tool/software:

Hello TI Team,

Since we are planning to use a 25MHz oscillator as the input clock source for DP83TG720R, we'd like to know, which power rail should be used to supply the oscillator?

What is the maximum input voltage level on XI pin?

Thank you in advance.

Best regards,

Mehdi

  • 0
    TI__Genius 13135 points

    Hi Mehdi,

    Mehdi Noroozi said:
    Since we are planning to use a 25MHz oscillator as the input clock source for DP83TG720R, we'd like to know, which power rail should be used to supply the oscillator?

    I would recommend having a separate voltage supply for the oscillator. I don't believe it's been tested being tied directly to the power supplies before. 

    Mehdi Noroozi said:

    What is the maximum input voltage level on XI pin?

    Please refer to section 6.5 of the datasheet

    Best regards,

    Melissa

  • 0 in reply to Melissa Chang
    Prodigy 60 points

    Hi Melissa,

    Thank you for the quick response. 

    So the question is, if we set the VDDIO in our system to 1.8V, which voltage level should be used to supply the oscillator?

    According to datasheet (see below), the power domain of XI pin is VDDA. We assume, the VDDIO could then be used to supply the oscillator. So could you please let us know if this is correct, or should it be always supplied with 1.8V?





    Thank you in advance.

    Best regards,

    Mehdi

  • +1 in reply to Mehdi Noroozi
    TI__Genius 13135 points

    Hi Mehdi,

    Mehdi Noroozi said:

    So the question is, if we set the VDDIO in our system to 1.8V, which voltage level should be used to supply the oscillator?

    The oscillator VIH value is 1.3V. So it shoud be from 1.3V to VDDIO, or 1.8V.

    Mehdi Noroozi said:
    According to datasheet (see below), the power domain of XI pin is VDDA. We assume, the VDDIO could then be used to supply the oscillator. So could you please let us know if this is correct, or should it be always supplied with 1.8V?

    It should be ok to supply XI pin with VDDIO as long as the Power cap requirements from our datasheet are followed.

    Here is a schematic checklist which includes the power cap requirements aswell.

    DP83TG720_Schematic_Layout_Checklist (6).xlsx

    Best regards,

    Melissa

  • 0 in reply to Melissa Chang
    Prodigy 60 points

    Hi Melissa,

    Thank you for the great help.

    Your answer already resolved our issue with 'XI' pin.

    Best regards,

    Mehdi