Adjustable shunt reference in SOT-23-3 — the ±1% matters
Its ±1% tolerance at the 2.495 V internal reference sets the accuracy floor for the entire regulation loop — every resistor divider, every temperature coefficient in the feedback path, works against that initial tolerance. Rated for 100 mA continuous cathode current with a minimum bias of 700 µA, this part can drive optocoupler LEDs in isolated power supplies or sink the base drive of a pass transistor in a linear regulator. The 36 V maximum output voltage covers most 24 V and 48 V industrial rails with margin.
Industrial temperature grade — motor drives and outdoor gear
The SOT-23-3 package keeps the thermal mass low and the board footprint small, but the junction temperature must stay within the 125°C ceiling — the 100 mA output at high ambient will require attention to the copper pad area under the package.
The base product number TL431 spans multiple tolerance grades and packages, but this specific A-grade SOT-23-3 variant is the one to lock into the BOM for the ±1% accuracy requirement.