WEBENCH® Tools/LM25116: The circuit is not able to support the designed output current

Sithara M

Prodigy 30 points

Part Number: LM25116

Tool/software: WEBENCH® Design Tools

Hi,

We have designed the circuit to work as follows;

Input Voltage : 16-32V

Output voltage : 5V

Output Current : 20A

We are able to get a constant output voltage at no load. But when we add load to circuit it is only able to support upto 5A. When we increase the load above 5A the output voltage starts dropping.

Please give a solution for this issue. The circuit and details are attached with this email.

buckpdf.pdf

Thanks,

Sithara M

over 4 years ago

0 Ankit Gupta95 over 4 years ago

TI__Expert 4555 points

Hello Sithara,

Can you please let me know the part number of the inductor you are using? Is it the same as given in 'buckpdf.pdf' file?

Best Regards,

Ankit Gupta

Application Engineer

0 Sithara M over 4 years ago in reply to Ankit Gupta95

Prodigy 30 points

Hii Sir,

Yes we are using the same inductor as mentioned in the file. All the components used are exactly same as given in 'buckpdf.pdf' file.

Regards,

Sithara M

0 Ankit Gupta95 over 4 years ago in reply to Sithara M

TI__Expert 4555 points

Hello Sithara,

Do we still have this problem? If Yes, please share your schematic and board layout for review.

Best Regards,

Ankit Gupta

0 Sithara M over 4 years ago in reply to Ankit Gupta95

Prodigy 30 points

Sir,

Yes the issue is still persisting. Please go through the schematic and give us a solution

Sithara M

0 Ankit Gupta95 over 4 years ago in reply to Sithara M

TI__Expert 4555 points

Hello Sithara,

1. Can you please share your PCB layout?

2. What is happening when the output is not correct? Current limit? Oscillation?

3. Please provide the waveforms of SW, Boot, Vout and Inductor Current.

4. Can you please double-check from webench to be sure you have the correct values.

5. Are you seeing this issue on custom made EVM or TI EVM?

Best Regards,

Ankit Gupta

0 Ankit Gupta95 over 4 years ago in reply to Ankit Gupta95

TI__Expert 4555 points

Hello Sithara,

Its been a while we had any update on this. Closing this thread for now so that TI monitor won't keep monitoring this thread. Thanks!

Best Regards,

Ankit Gupta

Application Engineer

0 Ankit Gupta95 over 4 years ago in reply to Ankit Gupta95

TI__Expert 4555 points

Hello Sithara,

I have not heard back from you, I will have to close the thread. Please feel free to re-open the thread whenever you are ready with the required information needed for further debugging.

Best Regards,

Ankit Gupta

Application Engineer

Power management

Power management forum

WEBENCH® Tools/LM25116: The circuit is not able to support the designed output current