NRF54L15-DK sleep current problem

RE: NRF54L15-DK sleep current problem

lahn — Tue, 25 Feb 2025 12:16:30 GMT

having a similar problem as pawpec with a sleep current of ~5μA,
I wanted to ask if it is possible for you to share your minimal example?

RE: NRF54L15-DK sleep current problem

pawpec — Tue, 18 Feb 2025 21:03:03 GMT

Simonr Could you share your source code for "nrf54l15_xxaa_application.hex", please? I can't get nRF54L15 to go below 120uA current consumption using sys_poweroff but with you hex it drops down to 0.8uA 🙂 Not sure what I'm doing wrong...

RE: NRF54L15-DK sleep current problem

Simonr — Mon, 09 Dec 2024 10:10:38 GMT

Hi, so in system off you should be able to get quite a bit of lower current, and I'm guessing this relates to RAM retention being enabled in your application. As opposed to the nRF52 series, RAM is retained by default in system OFF. It's safe to turn off RAM retention by setting both RET registers to 0 in order to disable RAM retention in system OFF mode. https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/memconf.html#ariaid-title4

You can also try this hex and see if you get the specified 0.6uA?devzone.nordicsemi.com/.../nrf54l15_5F00_xxaa_5F00_application.hex

Best regard,

Simon

RE: NRF54L15-DK sleep current problem

secondbest — Fri, 06 Dec 2024 14:20:39 GMT

Thanks for the response. Shortly, you are saying that If supply voltage is 3V, 6uA idle current is normal.

RE: NRF54L15-DK sleep current problem

Simonr — Fri, 06 Dec 2024 14:07:18 GMT

Hi again

So, internally in the SoC, the nRF54L15 low-power domain (always on domain which can wake the rest of the system from System OFF mode) draws energy form the DECD capacitor. So periodically, VDD will draw some power to charge up this capacitor again, as the capacitor will charge and discharge between 0.7V and 0.9V.

Best regards,

Simon

RE: NRF54L15-DK sleep current problem

secondbest — Thu, 05 Dec 2024 14:29:48 GMT

Sorry for delay. App is doing nothing. I disabled serial, that's all. This is brand new nrf54l15-dk. Why is there clock calibration for nrf54-dk? I am not seeing it for nrf52840-dk?
Thanks for support.

RE: NRF54L15-DK sleep current problem

Simonr — Tue, 03 Dec 2024 08:59:53 GMT

How do these every 4 second spikes look if you zoom in on them, and what project are you using for testing here? Every 4 seconds is oddly familiar to the default clock calibration period that's used by default on the nRF54L15, and is required even when LFRC is not used. This is already discussed in this case where my colleague Vidar discusses a similar issue with a DevZone user and has some suggestions to how to disable calibration.

This is described in this erratum by the way. As long as you're working at room temperatures, it should be fine increasing the time between each calibration in your use case. This was not yet discovered when we did and uploaded the demo on Youtube, but you should see the same if you remove this calibration altogether.

Best regards,

Simon