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Associate II
September 19, 2024
Solved

VREFBUF not available

  • September 19, 2024
  • 2 replies
  • 1546 views

I have an STM32U535RET6 chipset and I'm trying to enable it's voltage reference buffer, but I can't. I have the latest version of the STM32 Cube IDE, and I'm stuck at the "VREF+ is double bonded with VDDA in this package" message. What's interesting is that a colleague of mine, somehow can enable the VREFBUF-er. I've attached 2 screenshots below, as well as the .ioc file. It's the same chipset, so I'm relay confused about the actual problem. Can somebody help me out please?

 

PXL_20240918_122735513.MP.jpg

Zer0_1-1726724982322.png

 

Best answer by AScha.3

>genuinely don't know what to do with the VREF+/VDDA.

Nothing - its connected/bonded to VDDA. And this should be  = VDD. (see ds for possible VDDA range)

 

see ds:

AScha3_0-1726732307334.png

 

+

AScha3_1-1726732596821.png

>interesting is that a colleague of mine, somehow can enable the VREFBUF

In this 64pin case? Yes you can, to test: will it survive the short to VDDA or not...

but it will not change the value on VDDA, if VDDA is supplied in your circuit/board - as it needs to be.

 

2 replies

STTwo-32
Technical Moderator
September 19, 2024

Hello @Zer0 

I'm not using my PC now (so i can't open the .ioc file). But if you want to know way this option is geayed and you can't use it, you may have to put your cursor on the option you want to enable under mode tab and a pop up will apper with a full description of why this option is geayed and what to do to enable it.

Best Regards.

STTwo-32 

Zer0Author
Associate II
September 19, 2024

Thank you for the info! I have done that already, below is a screenshot regarding that. But it still makes me wonder why, since the same chipset doesn't have the VREF+ double bonded with VDDA in this package. Even so, I genuinely don't know what to do with the VREF+/VDDA.

Zer0_0-1726729516877.png

 

STTwo-32
Technical Moderator
September 19, 2024

For your college, could you send me his .ioc file. I think it is a bug is an older version.

Best Regards.

STTwo-32

 

waclawek.jan
Super User
September 19, 2024

In 'U535, the VREF+ pin - consequently VREFBUF - is available only in the 100-pin packages:

waclawekjan_0-1726731072327.png

 

JW