nRF9151 LACA A0 revision PSM current increase compared to A1 revision

RE: nRF9151 LACA A0 revision PSM current increase compared to A1 revision

Achim Kraus — Fri, 03 Apr 2026 06:38:15 GMT

Any new observations? Did you found out, why you see that higher energy consumption?

RE: nRF9151 LACA A0 revision PSM current increase compared to A1 revision

Simon D-M — Thu, 26 Mar 2026 15:57:22 GMT

Hi,

It doesn't seem like the A1A has any changes that would explain this change in current consumption.

A 70uA difference might indicate that the SIM cars is still powered. Can you share the AT commands that you use? And if you have access to the modem trace, can you also send the raw trace (.mtrace or .bin).

Best regards,

Simon D-M

RE: nRF9151 LACA A0 revision PSM current increase compared to A1 revision

Achim Kraus — Sat, 21 Mar 2026 05:59:10 GMT

I used now also two Thingy:91X, again one with a A0A and one with a A1A. And in both cases I get 8.5µA (measured at the battery plug as overall quiescent current).

Though you have different results, I assume it must be something special on your side.

(I would also test with Jared's nRF9151-feather , but all my A0A devices are in the field and I guess it will take one or two years for those devices to get back into my lab ;-) ).

RE: nRF9151 LACA A0 revision PSM current increase compared to A1 revision

Achim Kraus — Fri, 20 Mar 2026 18:45:44 GMT

[quote userid="151197" url="~/f/nordic-q-a/127523/nrf9151-laca-a0-revision-psm-current-increase-compared-to-a1-revision/563771"]It would be weird if it was something else[/quote]

According your tests, maybe. But I guess, it will be very hard for others to reproduce your result.

According my test with two DKs, it MUST be something else as a general issue with A0A and A1A. And I guess, it will be easy to reproduce for others.

So, maybe you try to strip your app to run on a DK and we will see, if your result is reproducable.

RE: nRF9151 LACA A0 revision PSM current increase compared to A1 revision

Simon D-M — Fri, 20 Mar 2026 15:33:29 GMT

Hi,

Honestly, this is the first time I'm hearing that.

I asked internally and will come back to you next week to give you an update.

Best regards,

Simon D-M

RE: nRF9151 LACA A0 revision PSM current increase compared to A1 revision

Reinis0 — Fri, 20 Mar 2026 13:30:53 GMT

COEX0 is used only to turn on GPS LNA on both devices, but only the chip antenna board has a LTE-M matching network.
It would be weird if it was something else, since I used the same board, the same components, same modem FW and same application and after resoldering A1A in place of A0A the current significantly decreased.

RE: nRF9151 LACA A0 revision PSM current increase compared to A1 revision

Reinis0 — Fri, 20 Mar 2026 13:24:30 GMT

Yes, during both measurements the devices were using the same FW and are using modem firmware version: mfw_nrf91x1_2.0.2.zip

RE: nRF9151 LACA A0 revision PSM current increase compared to A1 revision

Simon D-M — Fri, 20 Mar 2026 11:58:45 GMT

Hi,

Before going too deep in the details, are you using the same application on the two chips ? And, are you also using the same modem firmware version in both chips ?

Best regards,

Simon D-M

RE: nRF9151 LACA A0 revision PSM current increase compared to A1 revision

Achim Kraus — Fri, 20 Mar 2026 08:23:15 GMT

NCS 3.2.4, mfw 2.0.4, using two nRF9151-DK, one with A0A and one with A1A I get in both cases 3.4µA. At least on my side it seems, that there is no general difference in the quiescent current.

Maybe other source or a specific setup causes your difference. Do you use some COEX or other antenna tunning functions?

80µA is a value I remember from the Thingy:91X with enabled BLE. There it was caused from an antenna switch.