nRF52810(QFN32) - pin 32 - vdd

RE: nRF52810(QFN32) - pin 32 - vdd

Simonr — Tue, 15 Oct 2019 13:18:44 GMT

I'm sorry, but I can't unveil any proprietary information regarding how the pins are connected internally. The chip is specifically designed for all the VDD pins to be connected to power, which is why we recommend against this layout.

Best regards,

Simon

RE: nRF52810(QFN32) - pin 32 - vdd

pierre12345 — Tue, 15 Oct 2019 07:43:18 GMT

Hi Simon

Thank you for your kind reply

but still no way to understand how this Pin is connected internally ? if this PIN is connected to other vdd internally ?

best regards

RE: nRF52810(QFN32) - pin 32 - vdd

Simonr — Tue, 15 Oct 2019 06:57:22 GMT

Hi Pierre

I've gotten word from one of our hardware engineers, and here is a paraphrase of their thoughts on the matter:

There is a clear risk of degraded performance if pin 32 is not connected to the external power supply. We haven't done any testing with such a configuration and can't say anything about which parameters may be degraded by how much, nor about the probability of malfunction. We strongly advise against using the device like this.

I'm sorry that I can't be any more specific, but it seems to me like you should go about changing the device layout and rather doing the certification once more.

Best regards,

Simon

RE: nRF52810(QFN32) - pin 32 - vdd

pierre12345 — Fri, 11 Oct 2019 12:54:38 GMT

thank you a lot Simon, this reply matters a lot for us , not only for application itself , but also for satisfiying our end users .

For actual status , the PIN32 is just connected a capacitor of 4.7uF.

So fat as I can tell , I suppose that this pin is mainly for DCDC regulator part (for the reasons: 1\ it is next ro DCDC filter pins, 2 its capacitor is 4.7uF , not 100nF as with other VDD pins; it seems that it is for high voltage input)

anyway , please let me know if you have any clue

best regards

RE: nRF52810(QFN32) - pin 32 - vdd

Simonr — Fri, 11 Oct 2019 10:16:39 GMT

Hi Pierre

I'll ask internally for more information regarding your situation, but I would prepare for having to make a new layout and doing the certification process over again if I was you, to be honest. It might take a few days before I get a reply, so please be patient. I will update you as soon as I know something.

EDIT: What state is pin 32 in? Is it connected to GND or just not connected (left floating)?

Best regards,

Simon

RE: nRF52810(QFN32) - pin 32 - vdd

pierre12345 — Fri, 11 Oct 2019 09:04:05 GMT

thank you anyway Simon , the tricky thing is that the application board is certifiied by CE test , everything is OK , so if I change the layout , we need to remake the CE certification ,

so I m wondering if there is no risk to leave this pin unconnected

RE: nRF52810(QFN32) - pin 32 - vdd

Simonr — Fri, 11 Oct 2019 08:46:11 GMT

I'm sorry, but how pins are connected internally within the chip is proprietary information, so I can't help you out there Pierre. I strongly recommend that you do supply pin 32 with power however, as it is necessary to power all VDD pins in order to ensure that the nRF operates correctly.

Best regards,

Simon

RE: nRF52810 pin 32 - vdd

pierre12345 — Fri, 11 Oct 2019 07:06:29 GMT

Hi Julian , thanks a lot for your reply ,

yes , it is QFN32 pins package,

our application is power by 2 AAA batteries , so the power supply is between 2.2V - 3.3V

we did a lot test on every aspects , no issue found so far , even the CE certificat is tested OK

we didn't use DCDC option , and not use pin26 pin27 pin28

I just so curious how this PIN32 VDD is connected internally and which part of function it powers up , do you know any souce from which I can know it ?

RE: nRF52810 pin 32 - vdd

Julian — Thu, 10 Oct 2019 23:32:11 GMT

pin 32 (assuming you have the QFN32 part!) is VDD.
pin 9 is also VDD, and they are probably connected together inside, so only having one connected is still powering your chip.

BUT.. QFN32 is a pretty limiting package.. you lose IOs compared to the QFN48 version of the same device.. and one of those two VDD pins could easily have been used for another GPIO if it wasn't needed for power input...

Even if it "works" I'd expect you could be having problems with high current draw situations like tx.
how's your tx power compared to the same code running on a board that has that power pin connected?
How's your transmitted radio spectrum looking? are you getting spurrs or harmonics?

It's possible that the only difference is your board might not run right down to the lowest operating voltage specified.. but there's also a lot of other possibilities, and at the end of the day if you're running it without that pin connected it's running out of spec. you should really re-spin the board to fix that issue.