nrf5340 DK 1.0.0 draws more current than 2.0.0

[Frikkie Badenhorst]

Hi there,

We have recently acquired some new nrf5340DK's and we suddenly noted that the SYSTEM ON LOW POWER current increased from about 5 uA to about 25 uA. 

Attached below is an example project we received which we are using as reference. When uploading this onto the new DK 2.0.0 hardware, we are measuring a current of 24.25uA:

When uploading the exact same firmware onto the older 1.0.0 hardware, we are measuring about 5uA:

Could you please advise whether you can replicate this issue? Is this a known issue?

Our hw setup is as follow, with SB40 cut:

2063.button2 (1).zip2577.button2 (1).hex

[Frikkie Badenhorst]

Hi there,

Is there any update on this perhaps? We are able to replicate the issue on all 2.0.0 DK's, while the 1.0.0 DK's are still running fine with the lower power measured.

We suspect that the new 2.0.0 DK with an additional nrf5340 might add some leakage current to the measurement, but it is difficult to tell.

I really hope we can get a response soon as we are planning on deploying test devices in the field very soon, and it is thus important that we understand the current draw.

Regards,

Frikkie

[Priyanka]

Hi,

I tried reproducing the issue here, but there was not much a difference in the consumption and both showed similar results. Did you try reproducing this with another rev 2.0.0 DK? Also, are you trying in the Sourcemeter or the Amperemeter mode?

Best Regards,

Priyanka

[Priyanka]

Hi,

Sorry for the confusion. I am still measuring around 55nA and am not able to replicate the issue. I have asked internally in the meantime.

-Priyanka

[Frikkie Badenhorst]

Thanks Priyanka.

You can also refer to private ticket case id: 287278.

The support engineer Vidar Berg measure 2-3uA using this project, and which is what you should also measure.

It really looks as if your chip is not being powered at all.

Looking forward to hearing from you

[Frikkie Badenhorst]

You can also confirm the operation of the firmware by pressing button 1, which should toggle the LED on the devkit.

I do hope you are able to escalate this ticket internally so we can get this sorted out as soon as possible.

[Priyanka]

Hi,

I had a problem with the PPK. I can observe around 3.16uA for the rev 1.0.0 and 6.83uA for the rev 2.0.0. 

Could you try to switch to the nRF Only from Default? (SW6)

After doing this, I observe around 3.12uA (rev 1.0.0) and 4.57uA (rev2.0.0)

-Priyanka

[Frikkie Badenhorst]

Hi Priyanka,

I was just opening up yet another nrf5340 2.0.0 DK. (This was the 4th one now)

After cutting SB40, uploading the attached hex file via programmer, resetting and measuring the current in source meter mode with a 3.3V supply, we were measuring 23uA.

I then toggled switch 6 into the nRF Only position. After which I measured 8uA. We do however need the switch to be in the default position.

After setting the switch 6 back to the default position, we are measuring the 24uA again.

I retried the above test at a supply voltage of 3V, in which case the current stays at around 3-4uA in both switch 6 positions?

This is very weird behaviour - can you please confirm the supply voltage you are setting the PK to? Can you do the same test at a supply voltage of 3.3V and 3V?

Can you also confirm that your 2.0.0 DK has a date stamp of 2022.10?

I will also be redoing the test using a different PPK

[Priyanka]

Hi Frikkie,

You are right! I can observe the 25uA current consumption in the new revision compared to the 5uA in the old one. I will report this internally and will let you know soon. Thank you very much for your patience and also for alerting this.

-Priyanka

[Frikkie Badenhorst]

Hi Priyanka, thanks for the update. Please keep me updated on what to do from here as we are sitting with 20+ rev 2.0.0 devkits ready to be deployed as test devices.

[Priyanka]

Sure, the issue has already been discussed with the developers and we will inform you soon.

[Priyanka]

Hi,

It seems the problem is with the setup when testing with the PPK. Could you try shorting the following pins?

What happens is that, when you change the supply 3.3V from the PPK, it only supplies to the 5340 and the rest of the board is at 3V which causes a leakage current. Now when you short the pins, the entire board is supplied. The fact that this problem arises only in the rev 2.0.0 could be because in the new revision, the SEGGER MCU has been replaced by the nRF5340.

Hope this helps

-Priyanka

[Frikkie Badenhorst]

Thanks Priyanka, we will investigate this and keep you updated. Either me or Kimberly will respond.