BG95-M3: USB connection problem


My intention is to run AT-command and FW updates via the USB interface.

I’m using BG95-M3 on an own prototype, where pins USB_VBUS, USB_DP and USB_DM are used for the USB interface.

I have installed the driver Quectel_LTE&5G_Windows_USB_Driver_V2.2.2.

When I connect to a computer (WIN 10), there is no USB device registered.

What is missing?

  1. pls connect the quectel EVB to check that , if your usb device can be enumerated normally

  2. pls check the voltage of VDD_ext , Is there 1.8v output .

    if not , maybe your module has not boot normally .


My comments:

  1. I don’t have any Quectel EVB. Which one should I use to evaluate the BG95-M3 design?

  2. VDD_ext = 0.00V. VDD = 3.28V. I assume the module has a preprogrammed FW, right?
    Concerning the bad VDD_ext, what to check?

Hi woodman .

  1. Since the VDD_ext is 0v, your board is not running , plc check your VBAT input , like below , I attached one HW desigen doc for your reference

  1. pls contact local sale of quectel , and get one EVB kit , it is useful to you , I think , it will make your development smooth.


There was a layout problem and after fixing it the USB connection seems to be ok!

Thanks, then I can go further on!

This issue is solved.