VDDCSI, VDD33USB pin on STM32N6

AndersonKKK · ‎2026-04-02

Hi,

I do not plan to use USB or CSI, and the board only receives 1.8V power. So, I asked how to connect the VDD33USB pin, and I was told to just connect it to GND. However, I have two more questions.

I currently have the VDDA18USB and VDDA18CSI pins connected to 1.8V. Is it okay to leave them as they are, or would it be better to connect them to GND? (have to consider leakage in the Stop mode)

Also, should I connect VDDCSI to GND as well?

Thanks in advance.

FBL · ‎2026-04-03

Hi @AndersonKKK

When USB and CSI peripherals are not used on STM32N6, the recommended approach is to connect their associated supply pins directly to GND (VSS). This includes: VDD33USB VDDA18USB VDDA18CSI VDDCSI

You should not leave these pins floating or connect them to 1.8V if the peripheral is unused to avoid leakage or unintended behavior.

To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

Best regards,
FBL

View solution in original post

FBL · ‎2026-04-03

Hi @AndersonKKK

When USB and CSI peripherals are not used on STM32N6, the recommended approach is to connect their associated supply pins directly to GND (VSS). This includes: VDD33USB VDDA18USB VDDA18CSI VDDCSI

You should not leave these pins floating or connect them to 1.8V if the peripheral is unused to avoid leakage or unintended behavior.

To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

Best regards,
FBL