nrf52832 PCB

[ENENER]

Hi

I have two questions about nRF52832 QFAA Custom PCB.

1)

When I calculate load capacitance for external crystal.

Is this fomula(C1,C2 =2Cl - Cstray {Cstray = 4pF}) correct??

2) I know C6(=DEC2) in nrf52832 QFAA reference circuiry.

And DEC2 should be floated.

So can I leave DEC2 pin like this picture??

Thanks

[ketiljo]

1. Yes. For a crystal with CL = 8 pF, use 12 pF load caps. 

2. Yes, no problem. 

Note how C3 here is grounded only to the VSS_PA pin (31):