LM51521-Q1: Output noise issue

Hi Bolong,

Thanks for reaching out.

Can you please provide the files as a PDF?

I cannot access your drive.

Best regards

Moritz

5152otuput.pdfPlease check.

Hi Bolong,

Thanks for the picture.

Now i need to have the other files with the quickstart calculator.

Thanks and best regards

Moritz

LM5152-output issue.pdfLM5152-Q1_Excel_Quickstart_Calculator_for_Boost_Controller_Design.xlsxThank you for your quick response, I try to make all files in the first PDF. If you need the original version of the quick start tool, please use the .xlsx. 

Hi Bolong,

Thanks for the calculator file.

Under which conditions do you see the noisy output? Can you provide a schematic with BOM?

Also it would be good to see some more scopeshots. Vin, Vout, switchnode and COMP would be good.

Best regards

Mority

Schematic and BOM.pdfNoise .pdfThe noise appears when the voltage level is lower than the typical input voltage of 12V. At this moment, the LM5152 begins to engage. In the noise. pdf, the first picture shows input voltage at 12V, then 11V, and 9V.  I think the LM5152 is working and maintains the voltage at 12V even when there is noise in the output. 

Hi Bolong,

Moritz said:

Vin, Vout, switchnode and COMP would be good.

Can you please send these scopeshots?

Best regards

Moritz

DS1ED124413054_5.pdfThis is the output at 11.6V. Could you explain what the switchmode and COMP are? Thank you.

Hi Bolong,

Please measure the points 1-4 in one scopeshot with a timebase of 1us/div.

Best regards

Moritz

Appreciate the picture. Here are the measurements. 

DS1ED124413054_6.pdf