STM32G0B1VET6 USB boot

[Alex_7777]

Hi,

I am using an STM32G0B1VET6. All power rails in my design, including VDDIO2/VDDUSB, are supplied from 3.0 V (2.95 min).

I would like to use the USB interface and the built-in USB DFU bootloader for firmware updates.

AN2606 states that VDDUSB must be connected to 3.3 V. However, AN4879 appears to specify a USB supply operating range down to 2.7 V, with 3.0 V as the minimum recommended operating voltage in some cases. Based on that, I would expect USB to operate correctly with VDDUSB supplied from 3.0 V.

Could you please confirm whether USB DFU is supported on the STM32G0B1 when VDDUSB/VDDIO2 is powered from 3.0 V rather than 3.3 V?

The board will be powered from its own 3.0 V supply. For the USB programming connection, I am planning to bring out only three wires:

• USB D+
• USB D−
• GND

The USB 5 V VBUS line will not be used to power the board.

Are these three connections sufficient for entering the system bootloader and performing a firmware update through USB DFU, or is the USB VBUS line or a separate VBUS-detection signal also required?

Thank you.

[MM..1]

Why you first not test with 3V3 ??? Condition for boot is in AN2606
and VDDUSBIO writed in AN 3V3 mean require power, value isnt strict.

[TDK]

The data sheet has the correct information. AN2606 is just some copy/paste note.

3.0 V is sufficient for USB operation. VBUS is not used. Only D+/D-/GND need connected for correct functionality.

Technically, if the device is self-powered, you need to monitor VBUS before energizing the data lines per the USB standard, but this is not required in practice.