nRF52840 supply decoupling references

RE: nRF52840 supply decoupling references

bjorn-spockeli — Tue, 16 Jan 2018 07:04:36 GMT

@ziererf ( Florian): C9 has been set to 820pF in the latest development kit version.

RE: nRF52840 supply decoupling references

Florian Zierer — Mon, 15 Jan 2018 15:13:53 GMT

Hi Bjørn, thanks for the answer. We are already in contact with a sales representative but are still waiting for an answer...

RE: nRF52840 supply decoupling references

bjorn-spockeli — Mon, 15 Jan 2018 14:32:54 GMT

Hi Florian, the release of PS v1.0 will coincide with the nRF52840 entering mass production, please contact your local Nordic Sales Manager for information regarding this. I've asked around internally and it seems that C10 and C13 will most likely be N.C in the final ref.schematic. C9 appears to be TBD still. Note: This might be subject to change in PS v1.0.

RE: nRF52840 supply decoupling references

Florian Zierer — Mon, 15 Jan 2018 10:26:17 GMT

@bjorn-spockeli Is there any update on this about the n.c. decoupling capacitors. There is still no PS v1.0 available. Do you know when there will be a final PS? Our layout is also very space constraint so we also would like to not use space for not mounted items.

RE: nRF52840 supply decoupling references

bjorn-spockeli — Fri, 28 Jul 2017 06:29:05 GMT

Happy to help :) I would appreciate if you could mark the answer as correct/accepted by clicking the check mark in the grey circle to the left of the answer.

RE: nRF52840 supply decoupling references

PC — Thu, 27 Jul 2017 23:39:07 GMT

Ok got it. Thanks for the clarification!

RE: nRF52840 supply decoupling references

bjorn-spockeli — Thu, 27 Jul 2017 10:33:44 GMT

I have updated the answer.

RE: nRF52840 supply decoupling references

PC — Wed, 26 Jul 2017 16:21:51 GMT

Thanks! Understood. A few following questions:

Q2: would it be possible to find out the reason for change? I'll tie E24 (DEC6) to B5 (DEC4) when I made first prototypes, just like the OPS v0.5.1. And won't put a jumper. I'm wondering whether worthwhile shorting 2 pins on the nRF52840 Devkit too, and what to expect differently by doing so.

RE: nRF52840 supply decoupling references

bjorn-spockeli — Wed, 26 Jul 2017 12:39:57 GMT

Q1: It is a name change only, as you correctly pointed out it is to discern it from pin A18 which was also named DEC2.

Q2: This change is due to the internal supply between DEC4 and DEC6 (DEC6 previously labelled DEC2 in v0.5.0) has been removed from the final product. The supply must now be connected externally for the final device layout. For the Prototype silicon currently sampling, this change can be made to development boards without changing device behavior. For the Final silicon, this change must be made or the device will not be functional.

Q3: Since its an Objective Product Specification it means that . Thus I strongly recommend that you make room for the C9, C10 and C13 as these values may change. If these pins are labled as N.C in the final PS, i.e. v1.0, then the pins connected to the capacitors that are labeled N.C can simply be left floating.