minimal components for SWD to work

[Peter Kmet]

Hi,

I'm designing custom PCB with nRF52832QFAA chip and after custom PCB population I can't make SWD to get working. In order to eliminate where the issue is I would like to start to populate as few components on PCB as possible in order to make chip alive, then add the rest. My question is, will the bare chip start working (SWD) with just 32MHz crystal and loading caps?

Thank you.

Peter

[Peter Kmet]

Just making sure, remaining - do you mean caps on DEC1, DEC3, DEC4 ?

Thank you.

Peter

[Nguyen Hoan Hoang]

Yes, and call caps on VDD_nRF

[Peter Kmet]

I am missing caps C24 and C25. Should SWD still work?

[Nguyen Hoan Hoang]

Those pins are the gpio.  Don't know why you need those caps for.

[Peter Kmet]

Thank you, VDD caps made the trick !

[Jay Tyzzer]

The caps on the design above,  C24 and C25, (P0.25,P0.26) are there to filter some RF that was escaping from those pins via the internal bonding wires.  If the pins are not being used, then those lines may be terminated to ground.  This is only on the QFN package.  If this is not done the design may or may not pass some agency certifications.  

As the CSP package  does not have these bonding wires those caps are not needed nor do those GPIOs  need to be terminated to ground.  Hope this helped.