Edge Detection circuit causes dips in power line

Thread Starter


Joined Mar 6, 2016
I'm trying to put together an edge detection unit for a delay measurement unit using the CTMU of a PIC micro-controller.

The edge detection seems to work as shown in the image below, however i see a negative dip after the falling edge. I noticed that the dip is present in the Vcc power line as well. I think this is causing issues with my CTMU since its giving me negative readings for very short periods :(
Is it possible to remove this dip?

My setup is very simple for the result below. An arduino uno produced a pulse every 1us which is connected to an edge detection setup as shown below upload_2016-5-15_21-15-37.png

I also noticed that the strange wave produced after the falling edge is visible on my PIC uP whenever a pulse is produced on a pin :(