LMR50410-Q1: The RC filter at the SW pin

Pin Tsai (TW FAE)

Part Number: LMR50410-Q1

Hi Team,

My customer is using the LMR50410-Q1 in the On board charger. And they ask us if the RC filter at SW pin is ok to be added. I haven't clarify the reason why customer want to add this modification, but very likely it is for EMI performance improve.

Here is the schematic, and it is the 12V to 5V buck conversion.

Can you help to advise:

1. If that is ok to add the RC as above picture?

2. If yes, any consideration on the RC siziing?

Thank you!

8 months ago

0 Frank De Stasi 8 months ago

TI__Guru 64055 points

Hello

It is OK for the customer to leave a space on the PCB for an RC snubber.

The traces should be as short and wide as possible to the SW node and GND.

If the customer needs to use the snubber, they will need to take measurements on the bench in order

to calculate the values of R and C.

I have attached an application note that may be helpful.

Typically, only one snubber network is required.

Thanks

snubber_slua831a.pdf 6646.RC_snubber_design_revA.pdf

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LMR50410-Q1: The RC filter at the SW pin