[Design Review] nRF52840 Custom Board - Schematic & Layout Check

RE: [Design Review] nRF52840 Custom Board - Schematic & Layout Check

Elfving — Fri, 11 Sep 2026 09:23:42 GMT

Allright, then you can use 20pF for both, like I previously mentioned.

[quote user="Van Le"]

I have made the edits according to your instructions.

[/quote]

Could you send me the revised gerbers to confirm?

RE: [Design Review] nRF52840 Custom Board - Schematic & Layout Check

Van Le — Thu, 10 Sep 2026 17:34:50 GMT

Thanks for your help,

I have made the edits according to your instructions.

As for crystal
hfxo: X322532MOB4SI
lfxo: SC-32S32.768kHz20PPM12.5pF

RE: [Design Review] nRF52840 Custom Board - Schematic & Layout Check

Elfving — Tue, 08 Sep 2026 14:07:04 GMT

Just got to it now.

I believe C2 here should be 1µF.
For the external capacitors around the hfxo, change them to 20. Or you can send me the datasheet for the crystals for me to double check. The equation goes Ccap = 2*CL – C_pcb – C_pin, with which the two latter is often thought of as around 4pF in total.
For the lfxo, change it to 20 too.
Regarding the layout, you should connect this VSS connection directly to the center pad, no other part of the ground layer. It is a weird thing but it is important for the harmonics. You can for instance note how its done in the reference layout.
You might also want to add another component for antenna matching, like a parallel cap to ground, that you do not populate unless you need to later.

Address these changes and get back to me.

Regards,

Elfving

RE: [Design Review] nRF52840 Custom Board - Schematic & Layout Check

Van Le — Tue, 08 Sep 2026 10:27:27 GMT

Hi Elfving,

Just following up on this ticket. Have you had a chance to look over the design files yet?

Thanks!

RE: [Design Review] nRF52840 Custom Board - Schematic & Layout Check

Van Le — Mon, 07 Sep 2026 10:57:31 GMT

devzone.nordicsemi.com/.../Gerber_5F00_PCB1_5F00_2026_2D00_09_2D00_07.zip

devzone.nordicsemi.com/.../SCH_5F00_Schematic1_5F00_2026_2D00_09_2D00_07.pdf

Apologies, I missed a file during the upload.
Please allow me to submit the Gerber and schematic files.

Thanks

RE: [Design Review] nRF52840 Custom Board - Schematic & Layout Check

Elfving — Mon, 07 Sep 2026 08:55:37 GMT

Hello,

Sure, this is something we can do for you 🙂

Although I am not seeing this design archive you are refering to, just a few images. Would you be able to upload the schematics as a file (potentially a pdf) in order to get the resulution higher? And the layout as gerber files?

Regards,

Elfving

RE: [Design Review] nRF52840 Custom Board - Schematic & Layout Check

Van Le — Mon, 07 Sep 2026 04:30:06 GMT

devzone.nordicsemi.com/.../7288.SCH_5F00_Schematic1_5F00_2026_2D00_09_2D00_07.pdf

devzone.nordicsemi.com/.../1321.Gerber_5F00_PCB1_5F00_2026_2D00_09_2D00_07.zip

Here is my project.