STM32U5 ADC differential input polarity issue - RM0456 error

[TDJ]

I think RM0456, section 33.4.7 may be wrong describing ADC differential input polarity:
"When channel “i” is configured in differential input mode, its negative input voltage is connected to VINN[i-1]."

According to Figure 218 and my tests the opposite seems to be correct: negative input voltage is connected to VINN[i+1].

 

 

[Diane POMABIA]

Hello @TDJ 

Can you give us more details about your feedback. 

Can you confirm if  connection is according to the figure ?

Regards

Diane 

[TDJ]

@Diane POMABIA I verified that ADC differential input polarity is consistent with Figure 218.
However, the text description at the end of RM0456, section 33.4.7 which reads:
      "When channel “i” is configured in differential input mode, its negative input voltage is connected to VINN[i-1]."
in my opinion is incorrect. Instead of "VINN[i-1]" should be "VINN[i+1]".

That is, if differential positive input is (e.g.) IN3, negative input for this channel is IN4, not IN2.

[Diane POMABIA · Accepted solution]

Hello @TDJ 

Yes, I confirm this mistake that will be resolved in next revision of Reference Manual.

Regards

Diane