Precision shunt regulation with ±0.5% tolerance
The TLV431BIDBZRG4 is a low-voltage adjustable shunt regulator from Texas Instruments that holds output voltage to ±0.5% tolerance — a step tighter than the standard TL431's typical ±1% or ±2% grades. This makes it the part to reach for when the feedback divider in a power supply or the reference in an ADC bias network cannot tolerate the wider spread of the commodity-grade shunt. Output is adjustable from a 1.24 V minimum up to 6 V maximum, set by two external resistors. The shunt regulates by sinking up to 15 mA through the cathode, with a minimum cathode current of 100 µA to maintain regulation.
Industrial temperature range and SOT-23-3 footprint
The SOT-23-3 package (TO-236-3 / SC-59) is a three-lead surface-mount footprint that fits into compact layouts alongside passives. The shunt reference type means it behaves as a three-terminal programmable Zener: the cathode sinks current to hold the reference pin at the programmed voltage. No external pass transistor is needed for loads up to 15 mA, which keeps the BOM count low.