Noise on PCB during 2.4GHz RF transmission

Hello friends, 

I am using nrf52840-CKAA for my customize PCB. 

I am facing the noise during RF transmission on my ADC. The peak noise happen when I send a packet of data via RF antenna. 

Power_Tx = 4dBm

  

When I decrease the Tx Power to -12dBm, the peak noise was gone.

I wonder that MCU takes a lot of power during RF transmission so it affect to the stability of power line. 

In nrf52840-CKAA, currently I tie all VSS pin together instead of tie each of them directly to the GND plane. Is it the problem? 

I appreciate all your suggestions. 

Minhduc

Parents
  • Hi

    Can you share your HW files so we can do a review of schematics and the PCB you're using? Here is an image of how the ground plane and VSS pins should be connected. 

    Also, please share some more details on the ADC you're using. What are you measuring on it, and what is this external ADC exactly? And is it connected to the nRF52840 somehow? If so, to what pins on the nRF52840.

    Best regards,

    Simon

Reply
  • Hi

    Can you share your HW files so we can do a review of schematics and the PCB you're using? Here is an image of how the ground plane and VSS pins should be connected. 

    Also, please share some more details on the ADC you're using. What are you measuring on it, and what is this external ADC exactly? And is it connected to the nRF52840 somehow? If so, to what pins on the nRF52840.

    Best regards,

    Simon

Children
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