NFC's not working

[Dat_Boy]

Hi, I have tried to run nfc example, but it doesn't working, accidentaly i have found out that if supply 3V nfc not working, but if supply 2.7V and less it works, what is the problem?

[Stian Røed Hafskjold]

This is strange. Can you please post your schematic and layout and also a more detailed description of the software you are running? Thanks

[Dat_Boy]

Here is the schematic, it corresponds to datasheet schematic, hope you will find errors if it is.I use nfc example with url record 

[Stian Røed Hafskjold]

I can't see any errors in your schematic. Did you tune the NFC antenna according to this white paper? https://www.nordicsemi.com/DocLib/Content/White_Papers/nwp_026/latest/WP/nwp_026/nWP_026_intro

Is the example actually starting up in 3V, while only the NFC antenna is not working, or does the example not work at all? Do you get any log output?

When you say that it works on 2.7V, is that the output voltage of the boost converter you are using? Or the input to the boost converter?

Can you try to power the chip directly from a stable voltage source instead of using the boost converter? Just to rule out that this is caused by the switching noise from the regulator.

[Dat_Boy]

Yes, i tuned antenna according to this white paper. Example is starting, when i supply MC with 2.5V. It means that external supply about 2.7V due to diods. And i have tried to supply MC with boost converter and directly from a stable voltage source, the same result. It works but not stable, and when external supply more than 2.7V it doesn't work at all(

[Stian Røed Hafskjold]

Sorry, I have no idea what is causing this. It doesn't make much sense. Not really sure what I can do in trying to reproduce this either. You can send your board to our office here and I can have a look if you want.

[Dat_Boy]

Thank you), that was my bad, I've assembled  the new PCB and now it is working