The TL431ACDBVRE4: No official successor has been assigned, so this remains the primary order code for the ±1% tolerance, SOT-23-5 variant of the TL431 family.
±1% tolerance — the precision floor for the regulation loop
The ±1% tolerance on the 2.495 V internal reference determines whether this shunt reference holds the output within your voltage budget. The 600 µA minimum cathode current means the part stays in regulation down to light loads.
100 mA cathode current — what it drives and where it limits
Rated for 100 mA continuous cathode current, the TL431ACDBVRE4 can directly drive the LED in an optocoupler for isolated feedback loops. The 36 V maximum output voltage covers common secondary-side rails in AC-DC converters.
SOT-23-5 footprint — board area and thermal note
Housed in a SOT-23-5 (SC-74A) surface-mount package, the part occupies about 3 mm × 3 mm of board area. The 0.95 mm pin pitch is layout-friendly for two-layer boards.