Active production, precision reference for low-voltage rails
The Texas Instruments TLV431BCDBZTG4 is an adjustable shunt voltage reference with a ±0.5% tolerance, housed in a SOT-23-3 package. It operates as a low-voltage counterpart to the industry-standard TL431, with a minimum cathode current of 100 µA and a maximum output current of 15 mA, making it suitable for precision regulation in battery-powered and portable equipment.
The ±0.5% tolerance on the internal reference voltage (1.24 V min/fixed) gives tighter regulation than the standard TL431's ±1% or ±2% grades. For a 3.3 V rail set with a resistor divider, that translates to roughly ±16.5 mV worst-case at the output — enough to keep a 3.3 V logic supply inside spec without an external trim pot. The adjustable output range extends from 1.24 V up to 6 V. That 6 V ceiling limits this part to low-voltage rails — 5 V logic, 3.3 V, 1.8 V, or similar.
The SOT-23-3 (TO-236-3, SC-59) is a three-lead surface-mount package with a 0.95 mm pin pitch. It reflows cleanly with a standard hot-air station at 260°C peak — no thermal pad underneath, so the part lifts easily without cooking the board. The small body (2.9 mm × 1.3 mm) saves board area but means the junction-to-ambient thermal resistance is higher than a larger SOT-223 — keep the copper pad area generous under the anode connection if dissipating more than a few milliwatts.