±0.5% tolerance — what it buys the feedback loop
The ±0.5% tolerance on the internal reference voltage (2.495 V nominal) means the output voltage set by the external resistor divider stays tight across temperature and lot — no trimming needed in production for most power-supply and supervisory circuits.
100 mA cathode current — load-driving headroom
The 100 mA output current rating defines how much load the shunt regulator can sink while maintaining regulation. For a typical 2.5 V reference driving a feedback divider on a switching regulator, the cathode current is usually under 10 mA — so the 100 mA ceiling provides generous headroom for transient loads or driving multiple inputs.
SOT-23-3 package — rework and board-fit note
The SOT-23-3 package (also listed as TO-236-3 / SC-59) is a three-lead surface-mount footprint. It reflows cleanly with a standard hot-air profile — the small thermal mass means it reaches reflow temperature quickly, and the exposed pad on the cathode pin (pin 2) carries the heat away. Orientation is marked by a chamfer on the top face.