• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 332 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.

TPS40210EVM: Vout Peak-to-Peak

Frederic Beck
Prodigy 10 points
Part Number: TPS40210EVM
Other Parts Discussed in Thread: TPS40210

Hello,

i had some issues with the TPS40210EVM. I used the original eval-board (Vin: 8V - 14V / Vout: 24V / Iout: 2A).

I measured the Vout and the ripple of it and it seems to be a problem there. You can see the measurements in the pics below.

The ripple is over 2Vpp. I measured on the Vout (J2) not on the testpoints. According th the datasheet the ripple should be around 500 mVpp.

 

The ripple creates radiation that shouldn't be there. What can i do to reduce the ripple?

I tried different capacitors on the output, but it didn't work very well.

Is there a easy way to change the FB or the COMP to reduce the ripple?

If i use WEBENCH POWER DESIGNER for the TPS40210, it is a different schematic and not how it is described in the datasheet.

Data WEBENCH (Vin 8-14V / Vout 24V / Iout 2A)

Can someone help me out?

-Freddy

  • 0
    TI__Guru 65610 points

    Hello Frederic,

    The ripple in your second measurement is below 500mV.

    Every power supply creates in addition to the ripple a high frequency noise which is very difficult to measure. Please review this technical article: 

    How to measure ripple for better design outcomes
    Testing switching power supplies includes many different tests, one of them being the output-voltage peak-to-peak ripple. Output-voltage ripple is the alternating current (AC) component of the direct current…
    By in Technical articles > Power management

    Is it possible that you are using the first measurement method described in this article (the noise is mostly caused by measurement parasitics then)? If this is the case, please try method 2 with the minimized loop and measure at the output capacitor.