Vref- minimum on stm32f103

[j-fischer-gundlach]

Posted on February 06, 2014 at 09:26

Hello together,

i´ve been searching for information about the minimal voltage wich has to applied to Vref-. In particularly it is around the stm32f103CBT6. I´ve used the search function in the RefManual, but could only found out that Vref+ must be >= Vdd. How´s about Vref-? Has someone a hint to respective document? best regards, JFG

[chen]

Posted on February 06, 2014 at 10:30

Hi

''i´ve been searching for information about the minimal voltage wich has to applied to Vref-. In particularly it is around the stm32f103CBT6. I´ve used the search function in the RefManual,'' The information you are looking for should be in the data sheet for the specific part you have. There should be a section on absolute voltages - that is what you are looking for. Data Sheet NOT reference manual.

[j-fischer-gundlach]

Posted on February 06, 2014 at 11:47

The datasheet makes only an standment at the list entry for conversion voltage range. This range´s minimum is defined as ''Vssa or Vref- tied to Ground''. So i guess this is the information i´m looking for. Lowest potential is Ground.

[chen]

Posted on February 06, 2014 at 12:06

Hi

I have not looked at the data sheet. I do remember in another thread/post, clive1 saying that the ADC CANNNOT read negative voltages. By implecations - the ADC reference cannot be negative. This ties up with what you have found in the data sheet.