nRF52810(QFN32) - pin 32 - vdd

[pierre12345]

in application design , this pin is not connected to VDD , but application board works well ,

application's power range is 2.2V - 3.3V (AAA batteries), max current consumption is around 7mA.

so is there a risk for application?

and what is the role of this pin ?

[Julian]

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.

[pierre12345]

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 ?

[Simonr]

Hi

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

[pierre12345]

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

[Simonr]

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