Interfacing with 1.8V OctoSPI RAM

[Fin95]

Hello everyone,

I am designing a board using an STM32U5 / STM32H5 microcontroller and I have a question regarding the power supply architecture, specifically concerning the independent voltage domains.

My Scenario:

• Main VDD: 3.3V (required for correct USB functionality/transceiver management via VDDUSB).
• VDDIO2: 1.8V (supplied independently to interface with low-voltage external peripherals).

The Issue:
According to the reference manuals and datasheets, there are specific power-up and power-down sequencing requirements, as well as constraints on the voltage levels between different domains (e.g., VDDIOx vs VDD).

Is it fully supported to run VDD / VDDUSB at 3.3V while simultaneously running an OCTOSPI/HyperBus at 1.8V?

Thanks in advance for your help!

[mƎALLEm]

Hello ​@Fin95 ,

Your request will be escalated to OLS.

 

[Andrew Neil]

Previous discussions:

https://community.st.com/search?q=1.8V+OctoSPI