Hi! I am working currently on a stm32 F407, I am implementing USB Communication Device Class with the microcontroller being a device. The microcontroller is powered via the STLink but I wanted to change that and supply it through the usb I am using for virtual communication. On the data brief, it says that the board has a Flexible power-supply options: ST-LINK, USB VBUS, or external sources. I assume that I have to use the USB Vbus.
The reference manual says that :
On-chip 5 V VBUS generation is not supported. For this reason, a charge pump or, if 5 V are available on the application board, a basic power switch must be added externally to drive the 5 V VBUS line. The external charge pump can be driven by any GPIO output. This is required for the OTG A-host, A-device and host-only configurations. The VBUS input ensures that valid VBUS levels are supplied by the charge pump during USB operations while the charge pump overcurrent output can be input to any GPIO pin configured to generate port interrupts. The overcurrent ISR must promptly disable the VBUS generation.
My question is does that mean that I have to add a circuit to my board in order to connect the Vbus with a GPIO and that's how I am going to supply it through the USB or I did not understand well?
Thank you
