Why not use op amp as a comparator?

[tia_design]

op amp comparator disadvantage

Here is a question, sometime an op amp is used as a comparator, but most time a specific comparator is designed. So what is the disadvantage of using an op amp as a comparator?

 

[surianova]

Here is a question, sometime an op amp is used as a comparator, but most time a specific comparator is designed. So what is the disadvantage of using an op amp as a comparator?

This is because normally opamp has compensation capacitor which will slow down response time of the output or the rising/ falling of the output. As comparator, you no need it because it is a open loop system.

 

[IanP]

I wouldn't be so strict with not using opamps as comparators ..
Here you will find some very interesting explanations:
https://www.analog.com/library/analogDialogue/archives/37-04/comparator.html
Regards,
IanP

 

[sunking]

for the power, area, speed, opa is not a good choice for comparator

 

[suria3]

Good article from Ianp, cheers . But Sunking can you explain how does this "power, area, speed" effect the opamp as a comparator?

Regards,
Suria

 

[zorro]

This is because normally opamp has compensation capacitor which will slow down response time of the output or the rising/ falling of the output. As comparator, you no need it because it is a open loop system.

Correct. The most popular OA, the 741, had a version without the compensation capacitor (if I'm not wrong, it was the 748), conceived for use as comparator.
Regards

Z

 

[beckchm]

because of their advantages and disadvantages , for different purposes, you must choose the right configuration.
op for closed-loop

 

[Iouri]

What is requrements for the spped?? In some case it is not bad idea to use opamp as comparato, but you end up paying more.....

It totally up to you, your budget and your reqrements

 

[hi_hedonist]

agreed to iouri