How to confirm if received IC is of original ST Make, TL431ACZ in TO-92 Package?

[Jay_Puranik]

Dear All,

I searched the full datasheet for ST make TL431 IC, The Datasheet is 22 page PDF File of the Sept. 2022 version.

I need to know as to what is the authentic markings expected on the face of this IC? How to check and confirm if the received IC is of original ST Make and Authentic and not fake or counterfeit? Please guide me and send me your responses to my email ID: jay.puranik@taspowertek.com;  I can share a photo of what I have purchased. The Problem faced is, that I am not getting the desired DC Output Voltage in my SMPS Circuit with my standard values of Voltage Divider Resistors across Output and the Feedback Volttage to the Reference Input Control Pin of TL431 IC.  I am getting less than desired required DC Output Voltage, so, I am interested in finding the reasons.

Thanks & with best wishes, - Jay.

[Issamos]

Hello @Jay_Puranik 

If you want to be sure that you're buying the ST original products, I suggest you to contact your local ST marketing agent or buy directly from the ST website or the commercial brands that are recognised by ST.

Best regards.

II