How to reach system off current of 0.8uA with nRF54L15

[samuel4]

Hi

I have tried the system off example with the nRF54L15dk. The current with enabled GRTC is about 3µA. Do you have an example application to reach the specified 0.8µA?

Kind regards

Samuel

[runsiv]

Hi Samuel

Which version of the DK do you have and what sample have you tested? 

If your DK is engineering B it might be this errata 

Regards

Runar

[samuel4]

Hi

The Chip has "QFAABB" printed on the middle line - so it seems it is engineering B. However, the system off example switches into system off? I mean the issue is about system on mode.

Kind regards

Samuel

[runsiv]

True, i mixed up on my end. I'm thinking it could be that the device goes into emulated system off due to the usb cable I presume you are using. I will try to replicate it on my end. It could also be due to 

Regards

Runar

[runsiv]

Hi

I think the issue is RAM rentention. It need to be turned off the reach the numbers in the datasheet. I will test it myself tomorrow and get back to you. 

It can be turned off by adding the following to main

NRF_MEMCONF->POWER[0].RET = 0;

NRF_MEMCONF->POWER[1].RET = 0;

NRF_MEMCONF->POWER[0].RET2 = 0;

NRF_MEMCONF->POWER[1].RET2 = 0;

Update: This should fix the issue

Regards

Runar

[samuel4]

Thank you! It's working now. In order to wake up periodically, I had to keep RET2 enabled. Deep sleep current meets 800nA as specified in the datasheet.

Kind regards
Samuel