In the schematic and layout pdf files shouldn't pins 33 and 34 be connected to ground?

[Michael]

nrf51x22_qfab_schematic.jpg I was going over the schematic and layout pdf files for the nrf51x22 before I began to create my own board and noticed that Pins 33 and 34 are not connected to anything. Aren't both pins supposed to be connected to ground? or is this connection unnecessary? I'm planning on connecting both to ground because the datasheet says to and doesn't say NC, but I thought I'd ask to at least point this out.

[Hung Bui]

@Michael: I assume you were talking about the QFN package. Pin 33 and 34 should be connected to ground. Please take a screenshot of the layout and schematic you found that it's not connected and add to your question. Also please provide a link from where you download it.

[Michael]

link text I think this is the link. You can also get there via p. 77 of nRF51822 PS v.3.1. Also, if anyone who reads this cares to answer, are there specific oscillators for X1 and X2 that are tried and true for the nRF51822? I see the recommended capacitance and tolerance for both, but I'd like to minimize all potential issues for an initial prototype.

Edit: Am I missing something here? Because the same pins are NC on the pcb for the nRF51 DK.

[Hung Bui]

@Michael: at p.77 the 2 pins connected to the thermal die pad under the chip. You can see it going inside. This die pad connect to ground via the vias that you can see on the bottom layer.

Any oscillator match with the recommended capacitance and tolerance should work. You can buy the same oscillator used on our nRF51 DK if you want to be sure. Check out the BOM.

[Michael]

O I see, sorry for the dumb question, I can't believe I missed that. It makes sense to connect to ground there because of the multi-via connection of the exposed center pad to ground.

[Hung Bui]

@Michael: It can be missed :) If you are ok with the answer, please mark it as correct and close the case (there is a close button under the question).