2021-08-10 05:40 AM
Hi guys,
I have a short question regarding the STM32L552ZET6 power domaines. Can I use 1v8 to power the chip and connect a 3v3 power supply on the VDDIO2 which I will power on from time to time(when I need to use those pins)? And another thing if I do not use the USB transceiver on MCU do I have to connect the VDDUSB to the 1v8 or leave it floating?
2021-08-10 05:50 AM
Yes, provided you comply with the powerup/powerdown restrictions:
When VDD is below 1 V, other power supplies (VDDA, VDDIO2 and VDDUSB) must remain below VDD +300 mV.
When VDD is above 1 V, all power supplies are independent.
2021-08-10 10:41 PM
Hi,
Thank you for the answer that rule will not be a problem cause in order to get the 3v3 to the VDDIO2 pin the MCU has to be allready power-up to command 2 1v8 lines.
Thank you again.