TPS54331

This is a good question.  SwitcherPro takes into account the tolerance on switching frequency(specified in the datasheet) for the minimum ontime calculations.  Let me check with my Applications Guru to see what he thinks. 

For 24 V input voltage, I calculate that the minimum output voltage without pulse skipping is 2.12 V.  I would probably not recommend using the TPS54331 for this application.  If you canlive with 2 A output, the TPS54233 will work.

this TPS54233 part would work but my switcher pro tool does not have this part in its library??  Is there a way to import it?

I ONLY NEED 1.5aMPS.

I also could not find the part tps51116 in the tool.  Is this part supported? Is this part still your best DDR solution?

Thanks for the help

The TPS54233 is available now.  I do not know the release status for switcherpro, I think all the software folks are off today, so it will be Monday before I can find out the schedule.  If you need immediate design support, please feel free to contact me directly.  My email is j-tucker@ti.com

It doesn't look as if the TPS51116 is in SwticherPro today.  The best place to keep up with what parts are in SwitcherPro, is to look at the SwitcherPro overview page, in the "related products" section.  Thsi is updated whenever new products are added in SwitcherPro.