nPM1300 battery charge + USB host functionality and power delivery for non-charger USB devices

[whati001]

Hi All,

I am currently evaluating how I can charge a single cell with the nPM1300 PMIC with a USB-C connector, with the addition that the same USB-C connector should be also use for connecting USB devices/peripherals when not connected to a charger.

Meaning, the VBUS pin from the USB-C should deliver power to the battery when connected to an charger and should deliver power from the battery to the external connected USB device. So far, I understand that I can use the nPM1300 PMIC for charging the battery and powering the system. But how can I change the roles? Such that I can connect an external device to the USB-C and that the PMIC provides 5V to the VBUS PIN?

I have found the following blog post, unfortunately, it only explains how to use the PMIC without an USB connection:

https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/extend-battery-life-and-add-usb-c-charging-with-the-npm1300?CommentSortBy=CreatedDate&CommentSortOrder=Ascending

Thanks in advice.

[Hieu]

Hi whati001,

This is done on the Thingy:91 X. You can reference its design.

Hieu

[whati001]

Hi Hieu,

thank you very much for your feedback. I took a look at the hardware files at the thingy 91X but seem to be too stupid to understand how the thingy can provide power to an external connected USB-C device.

So I have illustrated the two use cases one more time below in case my explanation was bad.

I fully understand `Usecase 1`, the nPM1300 does the USB-C addressing via the CC lines and sinks the power from the charger through the VBAT pin.

But how `Usecase 2` work? What I am not getting is that in my opinion, either the nPM1300 or the nrf5340 have to source the VBAT pin of the USB connect J6. 

The only possibility I see is that the nPM1300 reverts the VBUSOUT and VBUS path, which is not possible based on the nPM1300 manua: https://docs-be.nordicsemi.com/bundle/ps_npm1300/page/nPM1300_PS_v1.2.pdf?_LANG=enus

---

So, I think I am trying to achieve something which is simply not possible with the Thingy91X. Based on this ticket, the nrf5340 (to which the USB lines D+/D-) are connected, does not support USB host mode.  Can the nRF5340 act as a USB host? 

But if I would use a CPU which supports USB Host mode, does the nPM1300 would support Usecase 2?

[Hieu]

Hi whati001,

My apology. I missed the requirement that your device needs to be able to supply power to other devices via the same USB port.

Since it might be relevant, may I ask whether you are using a nRF MCU for this system or not?

And what voltage is your MCU running at? Can it be 5V?

[whati001]

Hi Hieu,

no worries, I am happy that we are on the same page.

No, the MCU would not be from you, but how does this matter?

The MCU will run at 3.3/3.6V.