LinkSwitch-CV design with PI Expert
Hello,
while using PI Expert (Release 10.3.2.9 x64) to enter and optimize a design with the LNK626 part, we found the following issues:
1) DMAX limit check not performed
Modifying some parameter values (namely, increasing VOR) PI Expert produced a design with a violation of Dmax ( > 0.54) which was not reported; even after reoptimizing the design, Dmax violation was not corrected nor signaled.
2) NFB value
Letting PI Expert produce and optimize the design without altering any parameter value, the Sw produced a design with NFB = 25.
However, it issued the following warning:
Description: For Best EMI performance NFB should be equal to 18
Fix: Manually enter the value for NFB on the PI XIs Spreadsheet
Ref #: 573
a) If the best value is 18, why does PI Expert design with NFB = 25 ?
b) How can NFB value actually be edited?
We did not find a way to modify it from within PI Expert.
Is it necessary to transfer the design to PI XIs Designer? If affirmative, is there a way to export a design from PI Expert to PI XIs Designer?
Best Regards
Comments
Hello,
the warning is shown in PI Expert.
I attached the .uds file for which PI Expert shows the NFB warning.
With current parameters value the DMAX issue is not there (DMAX is within the allowed range), but if you manually force higher values for VOR the design will be readjusted causing DMAX violations and without issuing any warning (of course this is not such a severe issue if you know about it or anyway check the design results, but I think it can be confusing).
Attachment | Size |
---|---|
LinkSwitch-CV_PIDesign2.uds | 532 KB |
Is this request still being investigated (The NFB issue at least)?
Thank you
Hi adicarlo,
Yes, both the DMAX and the NFB issue is still being investigated. This might take some more time as we have to verify the changes we have to make.
Thank you
Hello,
while the actual issues concerning the PI Expert SW are investigated, would it be possible (focusing on the NFB issue only) to get a work around suggestion to still synthesize a reasonably optimized design?
Thank you
Hi,
The investigation and validation process will take some time.
As for now, as a work around you may use the suggested NFB = 18 and emulate your spec from PI Expert to PI XLS. In PI XLS, you can change your NFB.
Hi, we are currently working on the fix. We expect to release the updated version soon. I will keep you posted.
Hi adicarlo,
While we're investigating on this matter, may we request for a copy of your .uds file so we can debug the said error. I would help us see the errors (both in the Dmax and in the NFB that you mentioned)
Also, were you able to see the NFB warning in the PI Expert or in the PI XLS?