nPM1100 Operation

RE: nPM1100 Operation

fmighani — Tue, 23 Jul 2024 16:16:12 GMT

Hi Runar,

Thank you. Our issue is resolved. Feeding the device form VBAT is the way to go. We tried it and the current goes down in low load mode.

Thanks a bunch.

Please close this ticket.

Kind Regards,

Farhad

RE: nPM1100 Operation

runsiv — Tue, 16 Jul 2024 14:07:35 GMT

Hi, So the nPM1100will have a quiescent of 800nA if it is supplied by VBAT and no voltage on VBUS.

If a voltage is applied on VBUS then some features related to USB protection and VSYS regulation have to be enabled, so the quiescent cannot be as low.

So the PMIC team has the following question: Why do you supply the IC from VBUS if you do not plan to charge a battery? Can't it be supplied from VBAT ?

Regards

Runar

RE: nPM1100 Operation

fmighani — Tue, 16 Jul 2024 00:25:08 GMT

Thanks.

We have left NTC open. Therefore, there should not be any battery charging going on.

We feed nPM1100 from USB and there is no battery in the system. USB input is 5V. I suspect that VSYS is at 5.0 (we will measure).

When we are in deep sleep, we draw only 10uA. so, we are in low load mode for sure. According to the datasheet, in low load mode, nPM1100 quiescent current can be as low as 800nA (.8uA). we expect the nPM1100 to detect the low load and drop to what is needed (around 10uA-17uA). Do we need to run this in PWM mode for low load detection to take effect right away?

This is very important to us. That is why we picked this device.

Is it time to have a conf call?

Thanks.

Kind Regards,

Farhad

RE: nPM1100 Operation

runsiv — Mon, 15 Jul 2024 09:17:59 GMT

Update

If you are supplying from VBUS input, then when in low current the DCDC might go in low power mode. But the rest of the chip is still requesting biasing current and references for the VSYS regulator and the battery charger to operate. So it seems normal to us to keep current consumption around 500uA. It is surprising it goes down to 20uA after 1 minute.So i'm asking internally if they have input.

Edit:

Do you have any information regarding the voltage variations on VBAT, VBUS, or VSYS?

Regards

Runar

RE: nPM1100 Operation

runsiv — Fri, 12 Jul 2024 14:04:40 GMT

Thanks for the information.
I have forwarded the information internally and will get back to you as soon as I have something

Regards

Runar

RE: nPM1100 Operation

fmighani — Fri, 12 Jul 2024 13:53:08 GMT

Hi Runar,

Thanks for getting back to me.

We are using nPM1100 to generate 1.8V to feed the MPU. We have both options to feed nPM1100 from a battery or USB interface. When we put the MPU into deep sleep, it is powered via the USB interface (wall powered).

Please see below the configuration to answer some of your questions. I hope this helps to help us! Thanks. Kind Regards, Farhad

RE: nPM1100 Operation

runsiv — Fri, 12 Jul 2024 09:04:50 GMT

Hi Farhad

Could you clarify a bit regarding your setup. As of now I have the following questions:

1. Is it a battery only system?

2. Are you using

3. Are you using the DCDC buck to supply your MCU, if so what is the battery voltage, buck output voltage and what is the mode of the buck, automode or forced PWM?

Regards

Runar

RE: nPM1100 Operation

runsiv — Fri, 12 Jul 2024 06:34:39 GMT

Hi Farhad

I'm checking internally and will get back to you

Regards

Runar