https://devzone.nordicsemi.com/f/nordic-q-a/59920/nfc-trace-impedanceHi, I&#39;m working with nRF52840 with NFC. I don&#39;t have yet the external antenna to connect to (now I&#39;m using uFL), but I&#39;m not sure about the trace width that goes from the chip through uFL. Should it be 50 ohm? In nRF52840 Development Kit NFC pins anden-USTelligent Community 13Tue, 07 Apr 2020 10:38:09 GMThttps://devzone.nordicsemi.com/thread/243861?ContentTypeID=1Tue, 07 Apr 2020 10:38:09 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f28ca92e-05f4-4a73-b08a-4081a5b73da5ketiljo<p>The NFC antenna is different from the BLE antenna as it&#39;s differential and not 50 ohm. Also, the frequency is very low so the exact impedance doesn&#39;t matter as much.&nbsp;</p> <p>The inductance in the antenna is what matters for the NFC antenna. Since the antenna is differential, it&#39;s better to use a two pin connection instead of U:FL which is a single ended connection.&nbsp;</p> <p>The inductance of the antenna together with the NFC antenna tuning capacitors forms a resonant circuit that is tuned to the NFC frequency, 13.56 MHz. Any change in the connection wires to the antenna can be compensated with the tuning caps.&nbsp;</p> <p>So just lay out the tracks as a differential pair.</p><div style="clear:both;"></div>