Not Answered NRF52832 Hardware Design about using oscillator but not crystal

[frankly]

hi，dear.

 I designed the hardware according to the datasheet of NRF52832, version 1.4, Page 545,Figure 169: QFAA and QFAB QFN48 with internal LDO setup.

In the picture of Figure 169, the pin number 34 and pin35  is connected to 32MHz crystal. But I modifed the circuit using 32Mhz Oscillator. 

Is my design right?

thanks!

[Andreas]

Hi,

 

External clock sources or oscillators are not really supported for the 32 MHz clock. It might work, but if you do go this way make sure it satisfies the requirements in this thread: https://devzone.nordicsemi.com/f/nordic-q-a/49590/using-an-external-oscillator-tcxo-with-a-nrf52-as-input-to-the-hfxo

Also make sure you test radio performance thoroughly.

 

Best regards,

Andreas

[frankly]

hi,Andreas. Thank you for receiving your reply in time.

In current situation above the picture showed, my hardware doesn't work. nRF52832 crashed a few seconds later after the board is powered up. Because I don't know this problem which come from either the hardware or the program, I check the design firstly that want to guarantee the hardware design is correct. It's not time to test radio performance yet.

thank you again.

[Andreas]

Hi,

 

Aha. We'll the oscillator probably does not have anything to do with that, the crystal oscillator (internal) is not started unless you do so in your code. DEC4 is not correctly loaded though, get rid of C36 and change C55 with a 1.0µF.

 

Best regards,

Andreas

[frankly]

hi，Andreas。

nice to meet you again.

You mean that i should change code to use the intenal 64Mhz crystal (i.e.HFINT) meanwhile soldering down my external oscillator?

Thanks!

[Andreas]

Hi,

 

HFINT is automatically requested and started, unless you specifically request HFXO using TASKS_HFCLKSTART, HFINT will  be used. My main suspect with regards to the crash is the DEC4 capacitor though.

 

Best regards,

Andreas