Troubleshooting 32Mhz crustal

[VaibhavS]

HI,

In my custom board of nRF52805  , I am able to program basic UART application. chip is also generating internal voltages on DEC1 & DEC2 lines.

But i am not able to check BLE in any phone. It seems RF is not yet enabled.

I checked 32Mhz crystal as well, but its not oscillating. I had replaced with new crystal , but still same issue.

What could be the possible cause of clock not generating? Load capacitance is 12pF. 

Please suggest troubleshooting steps.

[Martin Sivertsen]

Hello,

Are you able to share a schematic of the board and design files or Gerber files + NC drill files?

Best regards,

Martin S.

[haakonsh]

Can you share the part number for the two scrystals that you've tried?

[VaibhavS]

Here's 32Mhz crystal part number XRCGB32M000F1SBBR0

[haakonsh]

It looks like the drive level of that crystal is too high. The max drive level of our clock is 100µW whereas that murata crystal has a maximum of 300µW. It is an indication that the crystal will struggle to start up properly. 

I suggest you find another crystal that adhere to the given specs: 64 MHz crystal oscillator (HFXO).