The TL431CDR-J: The ±2.2% tolerance on the internal reference sets the output voltage accuracy floor. For a 2.495 V minimum output, the worst-case spread is about ±55 mV before resistor divider errors. That is tight enough for a 5 V or 12 V rail in a non-critical supply, but not for a precision ADC reference — grab the TL431A (0.5% or 1%) for that job.
100 mA output current — driving the load
Rated for 100 mA continuous output current, this shunt reference can sink enough current to drive the optocoupler LED in a feedback loop or bias a small signal transistor. The 1 mA minimum cathode current means it stays in regulation down to light loads — useful when the loop is idle but the rail must stay stable.
Not for a motor drive cabinet, an outdoor telecom enclosure, or an automotive ECU — grab the TL431I (industrial -40°C to 85°C) or TL431Q (automotive) for those environments.
8-SOIC package — field-swap note
On a service call with a hot-air station and flux pen, it is a straightforward swap — no fine-pitch risk, no exposed pad. The pin 1 mark is clear on the top mold; just align the notch to the silkscreen and you are good.