Its key differentiator in this 'BQ' grade is the ±0.5% reference voltage tolerance at the 2.495 V nominal output — tighter than the standard ±1% or ±2% grades, which matters when you are setting the regulation point of a 3.3 V or 5 V rail and want to keep the feedback divider resistors in standard 1% values without trimming. The shunt topology means it sinks current from a supply through an external resistor, regulating the cathode voltage to the programmed level; it can also be configured as a series regulator or an error amplifier with a few external passives. Rated for 100 mA continuous cathode current and requiring only 700 µA minimum cathode current to maintain regulation, this part covers both low-power bias rails and moderate-load shunt regulators. The 36 V maximum cathode voltage gives headroom for 24 V industrial bus rails and 30 V automotive supply lines.
Package and footprint — SOT-23-5
Supplied in a SOT-23-5 package (also referenced as SC-74A, SOT-753), this is a five-pin surface-mount device with the standard pinout: cathode, anode, reference, and two no-connect pins. The SOT-23-5 footprint is shared across many of TI's TL431 variants, so a board layout can accommodate multiple tolerance or temperature grades without a PCB respin.
It is fully ROHS3 compliant, which means it meets the current EU RoHS exemption-free requirements — no lead, mercury, cadmium, or other restricted substances above threshold limits.