Re: What parameters are take care while designing a opamp as a comparator
Hi,
Are you sure the LM393 is an op amp? My LM2903/LM193/LM393 datasheet says something about a comparator.
AN74 is as useful as the datasheet for some things for the LM139/339. Look at the internal design, so simple and so effective. The main current source is a great block to borrow.
You know it's a "not recommended", don't you? Apparently it's of the category of doable with a spare op amp from a quad if needs or laziness or cost must. They're entirely different things.
Attachments
AN-74 LM139 etc A Quad of Independently Functioning COmparators snoa654a.pdf
Re: What parameters are take care while designing a opamp as a comparator
Yes, the LM393 is a comparator, not an op amp (it can be confusing since they usually use the same symbol for both devices.
The difference is that an op amp has internal compensation so it is stable with negative feedback, while a comparator has no compensation, making it faster as a comparator, but it is unstable in a linear mode with negative feedback.
Re: What parameters are take care while designing a opamp as a comparator
The LM393 dual comparator has almost the same circuit as the LM358 dual opamp except without the frequency compensation capacitor and without the push pull output.