[sdiy] Opamp as a comparator

[oleavitt at ix.netcom.com]

You might try the LM318 - this op amp has about a 50V/microsec slew rate.

Oren

John Speth <JohnS at molectron.com> wrote:
> 




Opamp as a comparator



<P>Hi list-


<P>I'm working on a quantizer project that uses a comparator.   I started the design using an LM311 hoping to exploit the OC output for driving 5V logic.  I quickly found out that a 0-5V output swing results in an asymmetrical hysteresis.  Now it's a plain old +/-15V comparator with positive feedback for hysteresis.  I might as well have used an opamp as a comparator to save the trouble of a pull up at the output.

<P>My questions are: Are suitably fast opamps just as effective as purpose built comparators in comparator applications?  How do I determine if an opamp is fast enough for my application?

<P>John Speth
> <A TARGET="Link" HREF="mailto:johns at molectron.com">mailto:johns at molectron.com</A>