• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 64 subscribers
  • Views 620 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.

TPS544B20 PGOOD threshold

K. Sasaki14
Guru 10200 points
Other Parts Discussed in Thread: TPS544B20

TPS544B20 PGOOD threshold is decided with reference to 600mV.
This is not change when we use Vout margining function. I think margin to threshold is too low in view of load transient.

Is it impossible to make PGH HIGH level higher?

Best Regards,
Kohei Sasaki

  • 0
    TI__Guru**** 191445 points
    You can make PGH either 12.5% (nominal default) or 7%. PGL has a much wider range. See section 8.6.33 and table 9 of the datasheet.
  • 0 in reply to JohnTucker
    Guru 10200 points
    John-san,

    Thank you for your answer.
    However I know we can set PGH 12.5%. I think 12.5% is small value. Is it possible to set more higher level?
    If we set VREF to 660mV by VREF_TRIM, the margin to PGOOD threshold is 2.5%. I think Vout variation is over PG threshold by load transient.

    Best Regards,
    Kohei Sasaki
  • 0 in reply to K. Sasaki14
    TI__Guru**** 191445 points
    I think it is very tight as well
  • 0 in reply to JohnTucker
    TI__Guru**** 191445 points
    From another member of our team:

    The PG/OV/UV can be adjusted, but the maximum upper limit for PG is 112.5% to a fixed 600mV.

    With either Vref_Trim or Margin command modifying the Vref to 660mV, triggering PG in transients can be expected behavior.

    A solution to this is set the nominal Vref to 80% of 600mV and design the voltage divider based this lower reference. Then choose -36%~7% range for PG.

    With this method, 10% margin command can be used with wider PG window.

    Hope this helps...
  • 0 in reply to JohnTucker
    TI__Prodigy 580 points

    The PG/OV/UV can be adjusted, but the maximum upper limit for PG is 112.5% to a fixed 600mV.

     

    With either Vref_Trim or Margin command modifying the Vref to 660mV, triggering PG in transients can be expected behavior.

     

    A solution to this is set the nominal Vref to 85% of 600mV and design the nominal output voltage divider based this lower reference. Then choose -36%~7% range for PG.

     

    With this method, 10% margin command can be used with wider PG window.