Support Required: STM32F746NGH6 USB OTG FS VBUS Issue
I am using the STM32F746NGH6 controller in my circuit to read external ADC (16bits) and transmits the same through USB. I have configured USB in OTG FS (device) MODE including AUTO detection.
Test Set-Up.
The USB is always connected and controller is powered on for testing and powered off after testing is completed
Earlier observation
This was practiced for about two months and was working ok without any issues
Current observation
The same is not able to recognize USB (i.e. auto detection is not happening)
Further Analysis
1) On probing the circuit, it was observed that 3V is present at USB V-Bus line always after the board is power on, even without the USB cable connected
Please clarify does it cause the issues. If yes, why and how
Queries
We would like you to clarify the following points about the user operation sequence
1) Be the controller power on, when engaging and disengaging USB cable
2) There is no need for any sequencing in user operation
NOTE:
We are in need of fix to avoid these issues in further production lot and please reply as soon as possible
