LM51581: Tested Efficiency much lower than WeBench results

KrnB

Intellectual 630 points

Part Number: LM51581

Tool/software:

Hello,

For Vin 5V input & 24V/10mA design,

the webench results show 87% efficiency for 5mA while I observe only 60% at 5mA. The Inductor & Diode used in webench & testing are same.
the excel calculator efficiency data states 60% which matches to my test data.

My design operates in DCM mode for current in range of 5mA. Please can you share which one is more accurate for referring efficiency - webench or excel calculator.

9 months ago

0 Federico Galli 9 months ago

TI__Intellectual 2250 points

Hi,

Thanks for reaching out and using e2e. I would recommend to trust your measurements and rely on the Excel calculator estimations.

For any other question you may have on the WeBench tool, I will loop in the WeBench team.

Kind regards,

Federico

0 Sateesh Goudappanavar 9 months ago in reply to Federico Galli

TI__Intellectual 2350 points

Hi KrnB,

Please be informed that LM51581 comes in a different topology and has multiple family of devices.

Could you please follow steps given in attached document and share the design link for above reported issue?

This will help us identify the issue faster.

Appreciate your support.

Thank you

Best Regards
Sateesh A G
Steps to Share the WEBENCH Design.pdf

0 KrnB 9 months ago in reply to Sateesh Goudappanavar

Intellectual 630 points

Please see link https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=5EB20190A2AFCB38

0 Umayal Ramanathan 9 months ago in reply to KrnB

TI__Expert 5810 points

Hi KrnB,

Thanks for sharing the design. We are able to replicate the issue. We are looking into the root cause for this. We will get back with more details by next week.

Best Regards,

Umayal

0 KrnB 9 months ago in reply to Umayal Ramanathan

Intellectual 630 points

Did you get chance to check the issue in detail?

0 Sateesh Goudappanavar 9 months ago in reply to KrnB

TI__Intellectual 2350 points

Hi KrnB,

Please be informed that the issue has been fixed and the updates will be released today. These updates will reflect on Production in next couple of days.

We will keep you informed on the same.

Appreciate your patient support.

Thank you

Best Regards,
Sateesh A G

0 Umayal Ramanathan 9 months ago in reply to Sateesh Goudappanavar

TI__Expert 5810 points

Hi KrnB,

The fix with respect to device LM51581 is now available on ti.com.

Kindly revert back to us for any further queries.

Thanks and Regards,

Umayal

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LM51581: Tested Efficiency much lower than WeBench results