LM393 comparator schematic?

Thread Starter


Joined Dec 12, 2005
Hello forum members,

I have to interface a shaft enocder with uC, but due to some reason the uC is not counting the exact pulses of encoder. I now want to use comparator to reduce noise and define the encoder signal. I have LM393 with me but unfortunately don't know how this could be used to achieve what I am trying to do, could someone please suggest a simple schematic for LM393, I mean which pins are used for what purpose (how connections are made on LM393?) or how encoder pulses be connected to comparator?

I would really appreciate your time and thoughts on this



Joined Dec 6, 2005
Go to this link: http://cache.national.com/ds/LM/LM193.pdf and you will find the National Semiconductor data sheet.

Without any idea of what your noise profile is, I suggest you add a little hysteresis to you circuit to eliminate noise. Maybe start with about 50% over the range of voltages you are interested in detecting.



Joined Sep 24, 2005
I mean, for this purpose quite enough a schmitt-trigger, like CD40106 (74C14).
If You choose the LM393, don't forget the pull-up resistor for output (open collector).