Adjustable shunt reference with tight tolerance
The Texas Instruments ATL431LIBQDQNR is an adjustable shunt voltage reference that regulates down to 2.5 V and up to 36 V, with a ±0.5% tolerance. The 80 µA minimum cathode current lets it operate from a very low bias — useful in battery-powered loops where every microamp is budgeted. It comes in a 4-X2SON package measuring 1x1 mm, which fits into compact sensor modules or multi-channel data-acquisition boards where board area is tight.
The 80 µA minimum cathode current is the lowest bias required to keep the shunt regulating. Dropping to 80 µA saves nearly a millamp per reference. For a design with multiple reference nodes — say, a multi-channel ADC front-end — that adds up to real power savings. The trade-off is that the output impedance is higher at very low bias, so the load regulation spec should be checked against the application's current draw. For a fixed load like biasing an op-amp input stage, the 80 µA floor is easy to satisfy with a single resistor to the supply rail.
The ROHS3 compliance is current — no exemption expiration to track.
Package: 4-X2SON (1x1 mm) — footprint and assembly
The 4-X2SON package (supplier device package 4-X2SON 1x1) has four leads on a 1x1 mm body with an exposed pad underneath for thermal dissipation. It is a surface-mount package designed for reflow soldering. The small footprint means the reference can sit close to the load — an ADC reference input or a comparator threshold divider — without long traces that pick up noise.