STM32H7A3ZIT6: undershoot and overshoot in the input pin

[Ryuichi]

Thank you so much for your continued support.

There is undershoot and overshoot in the waveform of the input pin on the STM32H7A3ZIT6. What is the acceptable duration (in nanoseconds) for it to be within specification?

Please also check the attached file.

Sorry to trouble you, but please provide your response.

Best Regards。

 

[Sarra.S]

Hello @Ryuichi, 

If the IO pin is configured as an input and it is a 5V-tolerant pin, there is no issue with undershoot or overshoot as long as the voltage does not exceed VDD + 3.6V, with a maximum limit of 5.5V. Given that VDD = 3.3V, this is within acceptable limits. For more details, please refer to the datasheet, table 22 "General operating conditions". 

[AScha.3]

Hi,

first question is: what is shown on the DSO ? real overshoot or measuring artifact ?

So can you show a pic from your measurement setup ? Just , when you make the capture, board , probe and cabels, connections, as they are.

And also : capture a square wave output from an i/o pin of the cpu, pin setting at highest speed, to compare.

[Ryuichi]

Hello Sarra.S san

Thank you for your response.

I have confirmed regarding the overshoot.

I have an additional question.

The measured undershoot is -0.5V, which is out of specification.

This is the same question as for the overshoot, but what is the allowable duration (in nanoseconds) for it to remain within the specification range?

Please also check the attached file.

Sorry to trouble you, but please provide your response.

Best Regards。