STM32L4 external SMPS

[Riccardo1]

Hi guys,

I'm working in a project with a STM32L412RBT6. Due to a misunderstanding, the company i'm working with, bought a big stock of STM32L412RBT6P.

I just discovered the meaning of that final "P" in the code and i'm trying to figure out how big the problem is.

I looked at the application notes and I noticed that there are two pins in which I have to connect an external 1.2V reference (in my project they are not connected GPIOs).

I could not understand if it is mandatory to connect this external reference in case I do not use any low power mode (we do not need them in this project).

Anybody have suggestions to help me ?

Thank you,

Riccardo

[TDK · Accepted solution]

You do not need to connect an external reference. There are some differences in the pinout, but if the subset of pins that you use are the same on both chips, no changes are necessary.

The VDD12 pin is used if you are using an SMPS supply. If you are not, the pin is not used and may be left floating. Details about SMPS can be found here if interested:

https://www.st.com/resource/en/application_note/an4978-design-recommendations-for-stm32l4xxxx-with-external-smps-for-ultralowpower-applications-with-high-performance-stmicroelectronics.pdf

[Riccardo1]

I was lucky then.

Thank you