How to test the power consumption of "System ON IDLE with GRTC (XOSC) and 256 KB RAM"

[666]

HI ALL,

   I used a system off demo and added the following content.

The power consumption tested was around 1uA, which should be normal according to the errata. Then, I wanted to test the idle state. Based on the above, I turned off the following content and tested that the power consumption was around 6uA.

This doesn't seem to match the specification book.

Is there any other way to test the power consumption of "System ON IDLE with GRTC (XOSC) and 256 KB RAM"？

note:v2.8.0,NRF54L15,QFAABB

[Sigurd Hellesvik]

Hi,

Can you try to measure the same for the blinky sample and let us know what current draw that has (when the LED is off in the blink cycle)?

Regards,
Sigurd Hellesvik

[666]

[Hieu]

The light you pictured is the debugger and shouldn't affect the board.

Do you know what VDD you are using? The datasheet lists current consumption at 3.3V. The DK runs 1.8V by default.

You can try to connect only GND and VOUT from the PPK and run it in source meter mode.

[666]

When DK runs at 1.8V, it is normal (3uA).

Why is there 6uA at 3.3V?

[Hieu]

That does not make sense at all. The current at 1.8V should be lower than the current at 3.3V, assuming the same operation state.

Are you absolutely sure?

[666]

The following is the same demo, showing the situation by changing the voltage

[Hieu]

The issues here are the spikes that you see all over the graph. They are not true spikes but rather false measurements due to limitations of the PPK.

I don't always see this issue, but when I do, changing the voltage in small steps help me find a threshold where such spikes occur. That doesn't help you see the real current draw at 3.3V, but the idea is, you can see that as supply voltage increase, current should decrease. Beyond this, at 3.3V, you would have to zoom in and selectively measure between the spikes.

I am asking internally what those spikes are and what can be done about them. I will get back to you once I get anything.

[666]

Hieu said:

you can see that as supply voltage increase, current should decrease.

From the graph, it appears to be limited to voltages below 3V?

Hieu said:

Beyond this, at 3.3V, you would have to zoom in and selectively measure between the spikes.

Is this the first two images? Is the power consumption 1.8uA at this time

[Hieu]

666 said:

Hieu said:

Beyond this, at 3.3V, you would have to zoom in and selectively measure between the spikes.

Is this the first two images? Is the power consumption 1.8uA at this time

No this also seems wrong.

Could you please measure VDDM and VDD_nRF with a voltmeter and let me know what the voltages are?

[666]

The two in the red box are both 3.43V.

The two in the red box are both 2.93V.

[Hieu]

I am trying to reproduce the issue on my end but haven't been able to yet. I only have earlier prototyping revisions of the DK, so I wonder if that is the difference. I will try to acquire a DK from the same revision as you.

Meanwhile, could you please share what it looks like when you measure in Ampere Meter mode? With all three wires connected, that is.

Do you also have a higher performance power analyzer, a different PPK, or a different nRF54L15 DK to switch up the setup? This is to help isolating where the problem is.

[666]