No last-time-buy window to chase, no forced redesign for a drop-in substitute.
Output range: 2.495 V to 36 V — covers most bias rails
This is a shunt reference, not a series regulator. The output voltage is set by two external resistors and can be programmed anywhere from the internal 2.495 V reference up to 36 V. The 100 mA cathode current rating means it can sink enough current to drive an optocoupler LED in a feedback loop or power a small auxiliary load.
±2.2% tolerance — tighter than the garden-variety TL431
The standard TL431B is 0.5%, the TL431A is 1%, and the base TL431 is 2%. At ±2.2%, this part sits between the base and the A-grade. For a non-critical bias supply or a secondary feedback path, it is fine — but if you need better than 2% initial accuracy, step up to the TL431A or TL431B.
SOT-89-3 package — small, but watch the tab
The SOT-89-3 (TO-243AA) is a three-lead surface-mount package with a large collector tab on the back.
Not rated for under-hood automotive or extended-temperature (125°C) environments — if the board sits near an engine or a hot power stage, look at the TL431Q or TL431M variants.