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TDK
TDKBest answer
July 19, 2024

Internally, there are protection diodes which protect over-voltage conditions. These are present for emergency situations to avoid damaging the chip. However, they are not meant to be used all the time. Eventually, they will degrade and wear out due to accumulation of thermal and electrical stress.

If you want to learn more, you can look up accumulation of damage due to ESD events to understand what is happening at the silicon level. Just because it works once doesn't mean it will always work.

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Andrew Neil
Andrew Neil
Super User
July 19, 2024

You need to give more details:

https://community.st.com/t5/community-guidelines/how-to-write-your-question-to-maximize-your-chances-to-find-a/ta-p/575228

 

@harry123 wrote:

Will my gpio pin gets effected if I give a voltage of 4v

What GPIO are you using? Is it 5V tolerant?

 

@harry123 wrote:

my board Is not working it is getting heated once i connect the supply through usb.

More details on that.

What else do you have connected?

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
harry123Author
Associate III
July 19, 2024

1) I'm using Stm32f429 disc 1 board

2)I wanted to measure a signal using internal adc with reference voltage of 3.3v . The gpios I'm using are pa2,pa3,pa6 all are of different voltages of 2.7v, 2v and 4v.

3) Suddenly the board stopped working and it's showing st link not detected when I start debugging.

images (1).jpeg

TDK
TDK
July 19, 2024

Pins are not 5V tolerant when they're in analog mode (e.g. being used by the ADC). Putting them above VREF can damage the board.

If you remove the voltage and the board works okay, good, but something may have been damaged.

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    TDK
    TDK
    July 19, 2024

    If you post the schematic here as a PDF or image, I'll take a look.

    Here's the STM32F4 hardware design guide. It should cover all that is necessary:

    dm00115714-getting-started-with-stm32f4xxxx-mcu-hardware-development-stmicroelectronics.pdf

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    harry123Author
    Associate III
    July 20, 2024
    • This is My custom board schematic. It's same as f429 disc1 board as I replaced both F429 main chip and stlink f1 chip from development board to my custom made board.
    • Now when I connected usb power supply the board is getting heated and it's showing stlink not connected. 
    • Plz look in to it.

    Thank you

     

    https://drive.google.com/file/d/1rJiLHR7v1m0_u9aUBMIOs7mpG5s_3u-o/view?usp=drivesdk 

    TDK
    TDK
    July 20, 2024

    I'm not clicking on a google drive link. You should be able to attach it here.

    Look for the "Drag and drop here or browse files to attach" just below the reply form.

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