Including battery USB charging on the nrf52840

[A.P]

Hello!

I'm looking for a way to include fast charging capabilities in my product, while still allowing USB2 data to pass between any host PC and the nRF52840.
As I understand from this ticket , nrf52840 does not support USB charge and so I can not hope to simply connect the D+ & D- lines to the nrf52840 and get more than 500mA from the USB connection.

To remedy this, I've looked at MP2722 or MP2724 as both a BMS (which I need) and a USBC-PD for when a USBC connection is used sync and, importantly, USB BC 1.2 to get higher currents when a USBA to USBC cable is used.

However, on MP support they say that the D+/D- can not be shared between the MCU and the MP2722.
Is there a standard way this connection is done so that both data to the MCU is available and USB BC is supported?

Thanks!

[Hieu]

Hi A.P,

I am afraid you have to ask Monolithic Power about their product. From our end, we can only agree that USB-PD doesn't require D+ and D- lines to work. However, the Monolithic Power chip might be doing something else with it.

If I misunderstood something, please let me know.

I will also relay your use-case to our teams.

Hieu

[A.P]

Hi Hieu!
I apologize, I tried to give as much data as I could and muddied my question.
I'm specifically asking about USB2 BC 1.2 capabilities as outlined in this document, for example.

As I understand it, the portable device uses the D+ and D- lines to perform some detection scheme when VBUS is detected to determine what type of Port it is connected to.
Different port types will supply different currents- SPD 500mA, DCP 1.5A, CDP 1.5A, DCP/CDP 1.5A.

Again, I may be wrong here, but it seems like the portable device must perform some action on the D- and D+ lines to be able to enumerate.

My question is then- do the nRF52840 and nRF52833 perform these actions when a USB2 is connected to them?
If not, and I understand this is not entirely a Nordic question, what is usually done to support these? does adding an external BMS like the Monolithic Power module I mentioned above and connecting the data lines to it solve this? if yes, how are the data lines shared between the IC and a BMS then?

Thanks

[Hieu]

Hi A.P,

A.P said:

My question is then- do the nRF52840 and nRF52833 perform these actions when a USB2 is connected to them?

The nRF52840 detects USB connected using VBUS only, purely analog. However, once connected, USB communication can start or not depends on the application software. Most often, this means some communication on the D- and D+ lines.

Is that what you are asking about?

A.P said:

If not, and I understand this is not entirely a Nordic question, what is usually done to support these? does adding an external BMS like the Monolithic Power module I mentioned above and connecting the data lines to it solve this? if yes, how are the data lines shared between the IC and a BMS then?

There has to be a USB hub to route data from the host to the correct chip.

On the occasion, may I recommend you take a look at our Power Management chip? The nRF1300, for example, is compliant with USB Type-C, is designed to work well with the nRF52840 and nRF52833 USB, and supports battery charging.

[Hieu]

P.s: The nPM1300 is used in the Thingy:91 X. In this product, one USB port is used for both charging the battery and communicating with the nRF9160. Therefore, it works well as a reference design.

Note that the nPM1300 is also capable of monitoring battery charge level as well. Overall, it seems like a suitable fit for your requirement.