NPM1300 current consumption in shipment mode

[Ben]

Hi,

we have npm1300 device on our customized board,

without using any of the regulators, LEDs are not connected.

Gpio 0 and Gpio 4 is connected to main MCU.

when activating shipment mode the current consumption gets to exactly 143uA

I can see that VSYS voltage is about 40mV

i also tried to configure GPIOs to open drain.

what should be the cause for this high current?

Thanks.

[JONATHAN LL]

Hi,

Is this only on one unit or do you see this behavior on mor then one? 

Did you use the one button sample to test https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/samples/pmic/native/npm1300_one_button/README.html , 

How are you measuring the current?


Regards,
Jonathan

[Ben]

Hi,

I have several boards and they all acts the same,

once when did step by step debugging until sending shipment mode command the current consumption was dropped to about 300nA

I am measuring the current with Otii Ace (https://www.qoitech.com/otii-ace/)

is it possible that this is related to analog measurements on the chip, because i read the current and voltage before entering shipment mode.

Thanks,

Ben.

[JONATHAN LL]

Ben said:

once when did step by step debugging until sending shipment mode command the current consumption was dropped to about 300nA

The 300nA value looks more like what we would expect. If you dont measure the before entering Shipment mode and only after, what values do you get then ? 

If the reason for the different measured values is due to how and when you measure the current\voltage then you should be able to test this by not measuring before entering shipment mode to see if the value is the same or if you get the expected results. 


Regards,
Jonathan

[JONATHAN LL]

What can be good to know is to see if going into ship mode without measuring V and I before entering ship mode. Does the issue still presist then? 

The 2 GPIOs 0 and 4 that are connected to the MCU : Is the voltage on these connections going to 0 in ship mode?

Regards,
Jonathan 

[Richard_P]

I just wanted to say that I had this exact problem. I was searching for hardware fixes and diode leaks for ages. In the end it was the internal ADC that was the culprit (VBATAUTOENABLE). I set ADCCONFIG to 0b01 which was firing the ADC automatically every second. The result was randomly I would get ship currents of either 145 uA or 0.52 uA. I assume this was depending on whether or not the ADC was operating at the time of going into ship mode?

Anyway - just before going into ship mode I now set ADCCONFIG to 0b00 and then wait a few ms to make sure no ADC conversions are happening.

Now I reliably get ship currents of 0.34 uA.

Please add this to the data sheet! (unless I have missed it????)

[JONATHAN LL]

Hi and thanks for you feedback it much appreciated. 

I will see if we can add this or make it more clear what conditions need to be met before entering ship mode. 

Regards,
Jonathan