TL431 reference with 4u7 filter cap.

[cupoftea]

Hi,
We have a TL431 with a 2k7 from a 12v rail into its cathode.
Cathode and ref pin are connected.
There is then a 4u7,0805,50v,x7r on the cathode to ground.
This ref then goes into a comparator.
Do you think the Vref may oscillate?

TL431

https://www.ti.com/lit/ds/symlink/tl431.pdf?ts=1668581480407&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTL431

 

[crutschow]

That information is given in the data sheet (below):
Did you look at that?
I shows that 4.7µF should be unconditionally stable for the TL431 and Tl431A devices, but the TL431B device would likely be unstable.

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[cupoftea]

Thankyou very much!
We are actually using the TL431MFDT.

https://assets.nexperia.com/documents/data-sheet/TL431_FAM.pdf

..My apologies, i didnt realise the stability situation would be different amongst TL431's

The TL431MFDT doesnt give any clue as to stability with capacitance on the cathode?
(I certainly cant find it in the datasheet)
Though page 12 appears to show that all of this nexperia family are stable above 330nF on the cathode?

 

[crutschow]

Though page 12 appears to show that all of this nexperia family are stable above 330nF on the cathode?

Yes, that does appear to be what it shows.