Not at all.
Read the whole sentence.
They are using the op amp to "behave" as a comparator, which is not an unusual thing to do with an op amp.
But it's still an op amp, not a comparator in the usual definition of the terms as applied to ICs.

Yes I read it - they mention an "error amplifier", A comparator will work as a linear amplifier if you roll it back with enough nfb - as demonstrated by my TL431 electret booster published in Elektor some years ago.

The usual TL431 application in a SMPSU puts it within a pretty tight nfb loop - its a comparator, but SMPSU output don't just switch on and off. When the TL431 is used open loop - its very obviously a comparator.

 

Yes I read it - they mention an "error amplifier", A comparator will work as a linear amplifier if you roll it back with enough nfb - as demonstrated by my TL431 electret booster published in Elektor some years ago.

The usual TL431 application in a SMPSU puts it within a pretty tight nfb loop - its a comparator, but SMPSU output don't just switch on and off. When the TL431 is used open loop - its very obviously a comparator.

We seem to be arguing about semantics here.

To me an op amp has internal compensation so that it is stable in a resistive feedback loop without any added external compensation.
A comparator does not and is not.
If you apply compensation to a comparator to make it closed loop stable, then you are converting a comparator into an op amp.
Using on op amp as a comparator doesn't mean it still isn't an op amp.

The amp in the TL431 is closed-loop stable when you connect its (REF) input directly to its output (CATHODE) and it will stably regulate the output as a shunt regulator.
Since it is stable with feedback and no added compensation, the makes it an op amp (as stated in the data sheet).

Notice the two Miller feedback capacitors in the TL431 circuit below to provide this internal compensation:

 

We seem to be arguing about semantics here.

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Nope - I was right and you were wrong. But any excuse will do , right.

 

Nope - I was right and you were wrong. But any excuse will do , right.

How in H do you think you were right??
Just you saying doesn't make it so (unless you happen to be named Trump)
Nothing I said was incorrect.