The MicroController is configured as USB Device. The board is self-powered.
With the initial Version we had a defect with the USB communication at customers site. We do not know what happend exactly.
By having a look into the design guidelines (spma056, page 37ff) we saw, that a resistor to USB0VBUS is recommended.
Can you please have a look in the 2 schematics attached:
- Initial Version: with that one a defect occurred
- optimized version: with that version we wanna go into redesign.
Are there other recommendations? Is the optimized Version enough protected?