STM32L4R5ZI USB Hardware Design

[CYeow.1]

Hi, I'm trying to design the USB OTG function on my PCB with STM32L4R5ZI. I saw the training documents and video on ST website and I'm confused about how to connect the TVS diode. There's a youtube video as well.

Since I'm using the OTG function, it will act as an Host or Device depends on the situation. I'm planning to use USBLC6-4SC6 as they suggested.

My question is since I'm using OTG function (I'm assuming it means it's self powered?), where should I connect my VBUS line from the USB connector? It's labelled as N.C. on the training documents for the TVS Diode VBUS pin and the VBUS pin from the USB connector is connected to an IO pin.

 

However, on the NUCLEO board, the VBUS from the TVS diode is connected to the VBUS line on the USB connector. So which one should I follow?

 

Thanks.

[Amel NASRI]

Hi @CYeow.1​ ,

If you didn't found yet an answer to your question, you should find it in the article Management of VBUS sensing for USB device design.

If you would like to get more details and explanation of USB hardware and PCB guidelines using STM32 MCUs, you need to refer to AN4879.

-Amel