nRF52840 Q1AAC0 power hardware issue?

RE: nRF52840 Q1AAC0 power hardware issue?

Andreas — Wed, 28 Oct 2020 11:19:38 GMT

Hi Matthijs,

Rev 2 (the MP version of engineerin revision D) is the latest and should be used and I was expecting that you should get this now. I would check with the distributor, and see if you need to specify in the order code or something.

I definitely agree that you should get the right revision for any build really, MP or prototype.

Best regards,
Andreas

RE: nRF52840 Q1AAC0 power hardware issue?

MatthijsvdV — Wed, 28 Oct 2020 10:17:16 GMT

Hi, thanks for your reply. You are talking about rev D but we would like to know which version chip we should use for the prototypes and production. On the site we can see there is a version 2-1.3 . Is this the latest version we get, when we order 20.000 pcs? We have to be sure we will not get the wrong chip and we do need to get the same chip in the coming year when we start making 20.000 pcs/month.

On DigiKey etc. we cannot know which revision we will get. How do we make sure we get the correct chip for our prototypes boards?

Thanks,

Matthijs

RE: nRF52840 Q1AAC0 power hardware issue?

Andreas — Wed, 28 Oct 2020 10:07:07 GMT

Hi Matthijs,

Based on just this information, it could very well sound like errata 197 is kicking in here. Unfortunately rev C/1 and D/2 are physically different devices, there are some workarounds that you can try out either for verifying the hypothesis or at least to be able to use your prototypes, but unfortunately to get properly low current consumption you will have to mount revision D devices.

I also noticed that in your design you have 100nF on VDD at pin B1. We have seen in a few cases that not having a larger capacitance close here (1µF in our ref. design) can trigger weird effects, so you could try that also and see if it solves the problem.

Best regards,

Andreas