EV2632-R-01A -> USB Communication

Hello,I just received my MP2632 evaluation kit.
I need a solution to detect the type of USB source in order to ‘select’ the correct charging current for my battery.In the case of a PC connection, I wanted to communicate with the PC by USB.I have not yet connected my battery to the kit.
By connecting a micro USB-USBA cable to U1 and a USB key to U3, I thought that the component would allow Windows enumeration of the USB key, which is not the case.
On the other hand, I can see that my USB key is powered.
Is this normal?

Hi David,

Thank you for contacting MPS. I am checking in on this issue for you and I will update as soon as I have an answer for you.

Thanks,
Brendan Schoemehl
Field Applications Engineer
Monolithic Power Systems | MPS Now

David,

The MP2632 should be able to detect USB input type since it has the DP1 and DM1 pins, so if you are using PC, then it is already detected as the default source and your input current limit is 500mA.

The DP2 and DM2 only present us as a DCP port by shorting D+D- together so when a portable device is plugged into U3, they know we can offer DCP current (1.5A). Can you explain what the USB key is in your application?

It may be easier to move this conversation over to an email chain, if you’d like to do so please contact us at mpsnow@monolithicpower.com.

Thanks,
Brendan

Hello Brendan,
I am in the process of designing a portable battery powered device.The battery must be recharged via the USB port.
This same USB port must also be able to serve as a communication link with a PC.

I thought, through the evaluation kit of the MP2632 to highlight this type of operation, ie:

  • Connection to a mains unit -> Charging the battery according to the current defined by R (lim)
  • Connection on a USB port: Recharge the battery at 500mA + communication via USB HID with the microcontroller on board the system.

Would the MP2632 meet my needs?
Could I do this kind of operation through the evaluation kit?
If this is not possible, what would you advise me as a reference?

Thanks,

David,

Checking in on this for you with my product line team and I will have an update for you soon.

Brendan

Brendan,

Did you receive more information from your technical teams?

David,

Here is my team’s response:
“U1 can be usb A port or micro USB port. He can connect his communication circuit directly D+ D-. because the communication only happens with SDP (standard port), our part won’t be messing with D+ D- line. Maybe add two 200k resistors between communication device D+D- and DP1 DM1.”

I hope this helps the operation of the MP2632 in your application.
Thanks,
Brendan