nRF54L NRESET pin reference design termination

RE: nRF54L NRESET pin reference design termination

Priyanka — Tue, 29 Jul 2025 09:46:20 GMT

Hi Tim,

It's true that there is an internal pull up so you wouldn't have to add an external one, but I wouldn't recommend not connecting the components shown in the reference, because as mentioned earlier, the RESET pin's proximity to the RF path and antenna makes the antenna vulnerable to spurious 2nd harmonic emissions in TX, which is precisely why the shunt cap is present there.

-Priyanka

RE: nRF54L NRESET pin reference design termination

jlegstrong — Thu, 24 Jul 2025 19:42:24 GMT

Thanks Priyanka,

One followup- if the pin is not used, can we leave it completely NC or is some termination still recommended? I see there is an internal pullup on the NRESET pin so it looks like we can just leave the pin floating. In our design it is broken out to a floating test point (not sure if having that stub matters)

RE: nRF54L NRESET pin reference design termination

Priyanka — Thu, 24 Jul 2025 10:19:46 GMT

Hi Tim,

I see that you were provided with an answer for the same in another ticket. These values were chosen due to coupling of the 2nd harmonic from the neighboring ANT pin to this pin.

If you have no further queries, is it okay to close the ticket?

Regards,

Priyanka