2.495 V ±1% — the precision tier that matters
The output voltage is set to a minimum of 2.495 V by the internal bandgap, and can be programmed up to 36 V with two external resistors.
100 mA sink and 700 µA cathode current
The device can sink up to 100 mA of continuous cathode current, which covers the majority of low-power shunt regulator and series-pass regulator applications. For a typical 5 V to 3.3 V shunt regulator, the 100 mA ceiling means the load current plus the 700 µA bias must stay under 100 mA. That is generous for a sensor or MCU rail, but tight for a multi-amp logic supply — the TL431 is a reference, not a pass element.
SOT-89-3 package and industrial temperature range
The SOT-89-3 (TO-243AA) package is a three-lead surface-mount footprint with a large collector tab on the centre lead for heat sinking. If the ambient exceeds 85°C, the TL431B grade or the automotive-qualified TL431-Q1 should be considered.
The TL431 family has been in continuous production for decades and is second-sourced by multiple manufacturers, which makes it a low-risk choice for long-life BOMs.