We're planning a design that uses the STM32U5 with built-in SMPS. Our device also uses USB, and the U5 packages we have are ones where VDDUSB is bonded to VDD so we must set VDD = 3.0-3.3V for the USB transceivers to work.
We have other devices on our PCB that can operate at lower voltages to save power and I was wondering if instead of tying them to VDD if we could tie them to the SMPS output (which I think is on VDD11 and I think would be the same voltage as whatever VCORE is configured to in PWR_VOSR - so somewhere around 1V).
Is this a really bad idea? My gut says this might be a really bad idea, but I am wondering if it is possible.
Thanks,
TG
