21540 PA hardware test

[William.wei]

hi support team,

may i ask how to test 54l15+21540 dtm? i have send code to customer, but they feedback to me that the output power is 15db, not 20db(using serial send command 09 14 to set output power) in readme.

if 15db is really case, how can we debug the 21540 and make sure it works normal?

Regards,

William.

[Hieu]

Hello William,

I will look into this and follow-up in 1-2 work days.

Regards,

Hieu

[Hieu]

Hi Willliam,

There was an issue with both the DTM sample and DTM app that affects the nRF54L15 and FEM setup. They are fixed in the latest version of NCS and the DTM app.

What version is the customer testing on? Can you check if they still see the same result with NCS v3.1.0 and DTM app v2.5.3 or newer?

Regards,

Hieu

[William.wei]

hi Hieu，

i can suggest customer to use ncs3.1.0. however, for DTM app i couldnot see what is improved when testing FEM. it only support 8 db  for version2.5.3.

Regards,

William.

[Hieu]

Hi William,

The change in DTM app is to address another compatibility issue between the app and the DTM sample.

It seems the TX Power limit is something that was overlooked. I have reported to the app development team but cannot comment on when that will be fixed. If you need it urgently, you need to contact our sales representative.

As a work around, you can build the DTM sample with CONFIG_DTM_POWER_CONTROL_AUTOMATIC. This will disable automatic FEM gain control from the nRF Connect for Desktop app. You can then manually change the FEM gain using the serial terminal using the vendor command FEM_TX_POWER_CONTROL_SET. You can refer to the sample's README for more information about this command.

Our apologies for the inconveniences.

Regards,

Hieu

[William.wei]

hi Hieu,

Thank you for you reply.

so, if customer need to test PA performance, the only thing customer need to do is testing DTM right?

another question is, how to test the sensitivity, do we have any docs on this?

Regards,

William.