nRF52840 and PA

I like to integrate the nRF54XXX with a LNA/PA combo (skyworks RFX2401C or 66110). Could you please tell me which pin should be used to control the RFX2401C TX/RX? Which has to be done in the softdevice?

Best Regards,

Weimin Peng

  • Hi,


    Any of the GPIOs on the nRF52840 can be used to control the FEM, you simply configure it in your FW. The control logic is described in the respective FEM datasheet. For RFX2401C, it looks like this:

    That should be compatible with our PA/LNA control, you can see how to configure the pin output in the Softdevice up here. This should work fine for most FEMs, but you need to control the pins according to the pins according to the control logic. The Softdevice only toggle TX and RX (acvite low or active high), if your FEM requires more control (e.g. sleep, high/low power, bypass etc.), you need to toggle this in your application or tying pins low/high as needed in your HW.


    Best regards,