nPM1100. From were this current is coming?

[p143]

Hi All.
I am using your NPM1100 PMIC as part of an IoT project in which low consumption is a critical restriction. The PMIC is working as expected, but there is a detail I don't understand. Once the charging cycle is completed and the green LED gets off, there is a remaining consumption of 1,7 to 1,9 mA through the VBUS, even if I disconnect the charged battery from VBAT and the secondary load from VOUTB. All this happens with the SW1 switch set to automatic, and If I set it to PWM -still with the secondary load disconnected-, the leak current goes even higher till 5,5 mA.
Could you tell me where this current is coming from? Can I be sure that this current won't load the battery, diminishing the module power autonomy once the primary charging power gets disconnected from VBUS?

Thanks

[Priyanka]

Hi Juan,

Sorry for the delay. Is it possible to attach your schematic for the nPM1100, in order to see the connections?

Best Regards,

Priyanka

[p143]

Hi  Priyanka

Here I am sending you the requested schematic.

Thanks for your time

Juan

https://www.dropbox.com/s/teuundlpkjc8e05/PMIC%20Leaking%20current.pdf?dl=0

[p143]

Hi priyanca.

Any news on this matter?

Regards,

Juan

[Priyanka]

Hi Juan,

Have you checked the solder bridge configurations for measuring the current? https://infocenter.nordicsemi.com/topic/ug_npm1100_ek/UG/nPM1100_EK/solder_bridge_configuration.html?cp=7_0_2_3_6 

Are you using a Power Profiler Kit to measure the current? If so, have you checked how to prepare the EK for measurement?

Also, what is the revision of your nPM1100?

[p143]

Hi Priyanca.

I'm not sure what revision means, but those are the two identifiers I can find on the EK:

- nRF6948v0.8.0 2021.33

- NAN212703970

To measure currents, I am using a standard multimeter.

Regarding solder bridges, I cut SB1 and SB2, but the leak current remains.

Analyzing the schematics I sent you, and since the leak current shows up with nothing connected to VBAR nor VOUTB pins and with the two leads also disconnected, the problem necessarily comes from one of the three submodules inside nRFPM1100.

As additional data, all seems correct if I measure the insulation from the mass of VBUS, VBAT or VOUTB pins, and changing ICHAR with SW7 doesn't change anything.

Have you been able to reproduce the leak in your lab? This simple check would be immensely clarifying.

Thanks

Juan