LMR51420: RC Snubber to prevent Surge

Hideki Hayashi1

Part Number: LMR51420

Tool/software:

Hi team,

Customer found output surge is big to generate EMI and wants to implement RC snubber circuit. Do you have recommendation for Snubber and layout?

Regards,

Hayashi

0 Ridge Lahti 8 months ago

Hi Hayashi,

Here is a good reference for sizing snubbers in switching power supplies: https://www.ti.com/document-viewer/lit/html/SSZTBC7

For the layout, make sure that it is close to the IC and as small of an obstruction from the SW node as possible.

Best regards,

Ridge

0 Hideki Hayashi1 8 months ago in reply to Ridge Lahti

HI Ridge,

Is the snubber circuit placed between SW pin and GND, correct?

Regards,

Hayashi

0 Ridge Lahti 8 months ago in reply to Hideki Hayashi1

Hi Hayashi,

Yes. It would look like this:

Here is an schematic example on an EVM. It is a little difficult to see since those components are DNP, but it shows the general idea:

Best regards,

Ridge

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