Precision shunt reference — the 2.495 V ±1 % anchor
The TL431AQDBZT is an adjustable shunt voltage reference from the TL431 family, with a minimum output of 2.495 V and a ±1 % tolerance — tight enough for most feedback loops in off-line power supplies, isolated DC-DC converters, and linear regulator error amplifiers. Rated for 100 mA continuous output current and a minimum cathode current of 700 µA, the part can drive optocoupler LEDs directly or bias a pass transistor without a separate pre-regulator. The SOT-23-3 package keeps the footprint small, making it a common choice for space-constrained designs where a TO-92 or SOIC-8 would be overkill.
The surface-mount SOT-23-3 package mates with standard reflow profiles and is compatible with both lead-free and tin-lead solder processes.