STM32F778, VDD 1.8V, USB not working

[MVore]

We have a design using the STM32F778. The FS USB works fine with VDD = 3.3V. When VDD = 1.8V, the USB does not work. VDDUSB is connected to 3.3V in both cases. On some boards, the FS USB will be detected by PC as a bootloader but it does not actually work. Anyone have success with one of the STM32F7 parts USB when VDD = 1.8V?

[Imen.D]

Hello,

Check the condition in this datasheet relevant to your device.

Regards,

Imen.

[S.Ma]

Check the power sequences to follow. Maybe the power up/down is wrong.

[MVore]

The power sequence is compatible with what is in the datasheet.

[Alex R]

What is your max HCLK when using Vdd=1.8?

[MVore]

180 MHz