What this AEC-Q100 shunt reference brings to the board
It delivers a stable 2.495 V reference with ±1% initial tolerance and can sink up to 100 mA of cathode current.
Temperature range and output capability
The 100 mA output current is enough to drive an optocoupler LED in a flyback feedback loop or bias a small load without an external transistor. The minimum cathode current is 700 µA, which sets the lower bound for the bias resistor in a shunt configuration. Below that, the reference loses regulation.
Package and footprint for production
Supplied in a SOT-23-5 package, also described as SC-74A / SOT-753. The 5-pin SOT-23 footprint is common across many TL431 variants, so the board layout transfers if you switch between commercial and automotive grades.