Can you help me check if it is right that the wires connect to the nrf52840 chips?

RE: Can you help me check if it is right that the wires connect to the nrf52840 chips?

JONATHAN LL — Fri, 10 Dec 2021 09:47:34 GMT

Hi Gaosheng,

Looks like you have followed configuration 6 of our ref design for the schematic. Looks OK, but have one comment, consider adding a matching circuitry for the antenna.

Remember to check the reference layout files as well to se what we recommend for best possible outcome.
You can download the files here: Compatible downloads - nordicsemi.com

Regards,
Jonathan

RE: Can you help me check if it is right that the wires connect to the nrf52840 chips?

lgs — Tue, 30 Nov 2021 09:03:54 GMT

Hi Marjeris,

Do you need my full design files?

Looking forward to your reply.

With best regards,

Gaosheng

RE: Can you help me check if it is right that the wires connect to the nrf52840 chips?

lgs — Sun, 28 Nov 2021 17:25:00 GMT

Hi Marjeris,

I have updated my design, I re-upload my schematic file here: www.dropbox.com/.../schematic.pdf

Could you help me review it again?

With best regards,

Gaosheng

RE: Can you help me check if it is right that the wires connect to the nrf52840 chips?

Marjeris Romero — Wed, 24 Nov 2021 10:09:07 GMT

You can download the nRF52840 QIAA reference layout from the nRF52840 product page on nordicsemi.no under the tab 'Compatible downloads'.

The files are Altium files. If you don't have an Altium license you can use use a free 6-months trial of Altium Viewer to review the files. And PDFs are also available in the downloaded folder.

RE: Can you help me check if it is right that the wires connect to the nrf52840 chips?

lgs — Wed, 24 Nov 2021 06:44:24 GMT

Hi Marjeris,

Do you know where to download CADs of nrf52840 chips?

With best regards,

Gaosheng

RE: Can you help me check if it is right that the wires connect to the nrf52840 chips?

Marjeris Romero — Fri, 19 Nov 2021 14:17:20 GMT

Happy to help! Please attach the new version of the files for a new review after you have fixed the issues above 🙂

RE: Can you help me check if it is right that the wires connect to the nrf52840 chips?

lgs — Thu, 18 Nov 2021 12:14:46 GMT

Hi Marjeris,

Thanks for your help!

Best,

Gaosheng

RE: Can you help me check if it is right that the wires connect to the nrf52840 chips?

Marjeris Romero — Thu, 18 Nov 2021 12:11:05 GMT

Hi again,

I have now reviewed your schematics. I have the following comments:

You NEED to connect XC1 and XC2 pins to a 32MHz crystal and following crystal capacitors for the chip to function, otherwise the chip will not start.
DEC5 should be connected to a 820pF decoupling capacitor.
If VBUS is not in use, please connect VBUS pin to ground.
You are missing several DEC decoupling capacitors. DEC1 should be connected to a 100nF capacitor, DEC4 and DEC6 connected together and to a 1uF capacitor. Please take a look at the reference schematic for nRF52840 CKAA in the PS or in the Nordic Infocenter.
You are also missing the decoupling capacitors in VDD_nRF (VSU in your schematics), so a 4.7uF, 1.0uF, and 2 x 100nF capacitors connected to each their VDD pin (please follow the reference design).
ANT pin should be connected to the matching network used in the reference design (L1, C3 and L5 components) and then to the antenna of your preference.

Please try to copy the components used in the nRF52840 reference design to ensure proper performance. Optional components are marked as "optional" in the reference design. All the other components need to be present for the chip to function properly.

Best regards,

Marjeris

RE: Can you help me check if it is right that the wires connect to the nrf52840 chips?

lgs — Wed, 17 Nov 2021 16:34:08 GMT

Sorry for that.

You can find the file here: drive.google.com/.../view

RE: Can you help me check if it is right that the wires connect to the nrf52840 chips?

Marjeris Romero — Wed, 17 Nov 2021 16:24:32 GMT

Hi,

I am so sorry but I not able to view your file. Could you make sure the file is uploaded correctly?

RE: Can you help me check if it is right that the wires connect to the nrf52840 chips?

lgs — Mon, 15 Nov 2021 16:00:38 GMT

Hi Marjeris,

Thanks for your help! Yes, I can share the whole file with you. I didn't put the whole file, because of the big size of the screenshot.

Best,

Gaoshengdevzone.nordicsemi.com/.../mypcb.pdf

RE: Can you help me check if it is right that the wires connect to the nrf52840 chips?

Marjeris Romero — Mon, 15 Nov 2021 12:47:10 GMT

Hi Gaosheng,

Yes, we can help you reviewing both your schematic and layout files. To do this it's better if you share your project files. If you don't want to disclose the whole design you can open a new private ticket and share your project files there.

I also recommend to familiarize yourself with the 'Reference circuitry' section in the nRF52840 PS and try to copy the reference design and layout from it to ensure optimal performance: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fps_nrf52840%2Fref_circuitry.html&cp=4_0_0_6_2

Best regards,

Marjeris