System_off example has increased power consumption when using k_sleep iso system_off

[Ypenburg]

I run the system_off example without the system actually going off, by removing all the calls to start the system_off worker. Instead of going to off, I let the system enter sleep mode (k_sleep()).

I enabled wake up on nfc.

After a reset, the system enters sleep (4-5uA sleep current). After waking the system by nfc, the sleep current sometimes becomes 200uA, sometimes stays at 4uA. See picture below.

It seems to be related to the state of the nfc peripheral as this is the only peripheral used.

Any idea how to prevent the system going to sleep with a 200uA sleep current?

[Simonr]

Thanks Renger

I'm now able to reproduce it and it does indeed seem like a bug with the nRF54L15 part of this application since I can't reproduce the same behavior with an nRF52 series DK unless there's something obvious I'm missing. I have reported it internally now and hopefully we'll find the root cause soon. For now, is there a specific reason you need k_sleep instead of system_off() as the system off function seems to work without a hitch.

Best regards,

Simon

[Ypenburg]

Hi Simon,

We are making an application were power consumption is critical, so most of the time the device will be in system_off. But now and then, the device has to wake up and do some work, like scan for other ble devices. In that mode we use the system_on sleep mode.

Besides that, I was wondering if I did something wrong .

Thanks,

Renger