X-NUCLEO-NFC08A1 : Change to Single-ended Antenna?

[mhbaek]

Hello,

I have a question about X-NUCLEO-NFC08A1 Evaluation Board.

The evaluation board is configured with a differential antenna by default, but I would like to change it to a single-ended antenna.

Is there any guidelines I can use when making changes?

Best Regards,

[Travis Palmer · Accepted solution]

Hello mhbaek,

Luckily the PCB layout does support single ended operation of the NFC08A1.

In this case, you have to remove the green marked components. AAT will not be available afterwards.

Also only half of the antenna turns will be used - should not be a problem.

Please make sure to set the "single" bit correctly. In this case, only RFO1 / RFI1 is connected to the antenna and will be driven.

 The remaining components need to be re-calculated according to AN5276 and the Antenna matching tool. 

There is also an dedicated appnote for single ended antenna operation AN5592 which is also valid for the ST25R3916B.

Please let me know if you have further questions.

br Travis