nRF5340-PDK power configuration to get +3dBm Tx Power

[Chris Pezzee]

I am trying to get the maximum Tx power from the nRF5340 PDK.

The nRF5340 specifications say that setting VREGRADIO.VREQH is required to get the last +3dBm of transmit power. I am calling nrf_vreqctrl_radio_high_voltage_set(NRF_VREQCTRL_NS, true) in the radio_test network binary to request a shift in power, but I didn't see any change in power output. I am powering the dev kit via J2, and switching “nRF Power Select” to VDD (the default setting on my board) but this doesn’t seem to enable VDDH.

 How should the PDK be powered to run in high-voltage mode?

Thanks!

[Jørgen Holmefjord]

Hi,

How do you determine that it is not working (error codes, etc)? Have you tried reading out the registers to see if they are set correctly?

I will try to reproduce what you are seeing.

Best regards,
Jørgen

[Jørgen Holmefjord]

I did a quick test on my DK. I do not see a full 3 dBm increase, but more in the range of 2 dBm:

Did you test this with the master-branch of NCS?

[Chris Pezzee]

As near as I can tell, yes:

~/nrf5340/ncs/nrf [master ↓·12|✚ 2…4]

10:41 $ git log  -1

commit bd95c844ba6b55f45b089dbcad6097640511e8aa (HEAD -> master)

[Jørgen Holmefjord]

Can you test with the hex-files I built?

radio_test_radio_high_voltage_nrf5340_dk_nrf5340_cpunet.hex

radio_test_nrf5340_dk_nrf5340_cpunet.hex

I used the "start_tx_carrier" command to start transmitting.