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daniel59
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the DA14580 inductor for 50Ohm antenna

Hello,

I use QFN40 DA14580 for my board.

I found that in the Known limitation document, it says For a 50Ohm antenna this works best with a 3.3nH shunt inductor to ground.

But in the AN-B-018, it says for QFN, we need 3.9nH shunt inductor to ground.

Which inductor do i need?

Daniel

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MHv_Dialog
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Both numbers are correct :-)

Both numbers are correct :-)

The WL-CSP34 package variant requires a 3n3H shunt inductor. the two QFN variants require a 3n9H shunt inductor. 

/MHv

daniel59
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er...so in known limitation

er...so in known limitation document, it doesn't show the inductor value for QFN?

and I found that AN-B-018 cannot be downloaded anymore?

MHv_Dialog
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Thanks for pointing this out.

Thanks for pointing this out. I will request a document update, and make sure that AN-B-018 is made available again (that is a very important document).

The shunt inductor will only improve the RF matching slightly. The output will be reduced by about 0.5dBm whith no shunt mounted. The difference between a 3.3nH shunt and a 3.9nH shunt would be very minimal.  

/MHv

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Hi Daniel59,

Hi Daniel59,

The document, AN-B-018  should be available again. Thanks for pointing out that it was missing.

/MHv