LM25066A: LM25066A VIN and SENSE decoupling cap placement

Neo.Wang

Part Number: LM25066A
Other Parts Discussed in Thread: LM25066

Hi TI experts,

I have LM25066A 12V hotswap design leveraged from existing project, where two 0.01uF caps are located on both side of Rsense.

Now let’s consider both C1015 and C1017 are stuffed. With two caps, can we place both of them close to LM25066A VIN and SENSE pins?

Datasheet has concern when only Vin cap is present, because in this case the LC filter will form and cause high voltage difference between VIN and SENSE pins.

But if we have both caps, the LC dumping will be cancelled from each other, hence I think the two caps can be placed close to hotswap controller pin.

Can you please share your comments?

Thanks,

over 3 years ago

0 Rakesh over 3 years ago

TI__Guru* 95661 points

Hi,

We have received your query on email and looking into it. We will get back by mid of next week.

Thanks for your patience.

Best Regards, Rakesh

0 Neo.Wang over 3 years ago in reply to Rakesh

Intellectual 750 points

Hi Rakesh,

Do you have any conclusion on this?

Thanks

0 Praveen GD over 3 years ago in reply to Neo.Wang

TI__Guru 57737 points

Hi,

If two caps C1015 and C1017 are considered, these two caps can be placed close to LM25066 device pins. But in that case, we could see some mismatch due to R717 resistor at SENSE pin.

If resistor divider is used across Rshunt, I prefer removing C1017 and following the standard practice we mentioned in the datasheet.

In general, we have not seen customers using C1017 cap.

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LM25066A: LM25066A VIN and SENSE decoupling cap placement