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Visitor II
February 18, 2025
Question

STM32L071 and 5V tolerant I/O in analog mode for adc use

  • February 18, 2025
  • 2 replies
  • 975 views

Hello everyone,

I have a question about 5V tolerant I/O in analog mode. When I look Figure 20. Basic structure of a 5-Volt tolerant I/O port bit in RM0377, i don't see the analog arrow as in figure 19.

 

kevin_delporte_0-1739894015475.png

Is it an error on figure or 5V tolerant I/O doesn't work in analog mode ?

Thanks for any response

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    2 replies

    Super User
    February 18, 2025

    Somewhere there is a note that pins in analog mode are not 5V tolerant. I will try to find it.

     

    Edit: Can only find this:

    TDK_1-1739896179781.png

     

    And this, which says the analog switch is only closed when the ADC is activated. The pin will still be 5V tolerant if the ADC is inactive.

    Solved: Are STM32L0 FT pins 5V tolerant in Analog mode whe... - STMicroelectronics Community

     

    Visitor II
    February 18, 2025

    I see this note, but my question is : Do 5V Tolerant work in analog mode ? Because I don't see a link to analog mode in figure 20

    Super User
    February 18, 2025

    > Do 5V Tolerant work in analog mode ?

    No, they are not 5V tolerant when in analog mode and being used by the ADC.

    Super User
    February 18, 2025

    Hi,

    >about 5V tolerant I/O in analog mode.

    Its just : only as digital input a pin can (FT_ pins) tolerate 0...5V signal. 

    As soon as you use any other pin setting, output or analog, ist always limited to vss-vdd (or vdda), 0...3v3 typical.

    The ADC itself anyway working on vssa - vdda , so nothing else possible as ADC-input.