I'm very curious about the same thing, if all the TL431 have the same layout. The two different TL431s in my article have the same layout, but don't match the schematics in the datasheets. I don't know if they changed the design in the past 26 years, or if there are different designs out there.
There's a small "TI" on the die, sideways above and to the right of the TLR431A text, which I assume is for Texas Instruments, but the lack of copyright is interesting. (I think chips are supposed to have a (M) for the mask.) Since I ordered the parts on eBay from China, I don't know who really manufactured them.
There's a small "TI" on the die, sideways above and to the right of the TLR431A text, which I assume is for Texas Instruments, but the lack of copyright is interesting. (I think chips are supposed to have a (M) for the mask.) Since I ordered the parts on eBay from China, I don't know who really manufactured them.