I'm using a lm555 IC in monostable mode. When my input varies from 5v to 0v the output goes from 0v to 5v. But this only happens perfectly if it happens just a pulse at the entrance, in case my input changes from 5v to 0v and continue at 0v for the rest of the time the output does not work correctly. What I want is the following, when my input changes from 5v to 0v and continue to 0v, I want my output to remain high only for the time I have determined.
What I have:
What I need:
I thought I could do that with transistor input, but I did not find a way to do it. If anyone knows something similar thank you.