Precision shunt reference for industrial power rails
The TL1431AIDT is an adjustable shunt voltage reference from STMicroelectronics, delivering a ±0.25% initial tolerance that sets the accuracy floor for the entire feedback loop — critical when the reference error directly multiplies into the output voltage error of a switching supply or linear regulator. Output is adjustable from a 2.5 V minimum up to 36 V, set by two external resistors, making it a drop-in replacement for the classic TL431 in designs that need tighter initial accuracy without a trim pot. Rated for 100 mA cathode current with a minimum of 700 µA to maintain regulation — the 100 mA ceiling means it can sink enough current to drive the optocoupler LED in an isolated flyback primary-side feedback loop without an extra transistor stage.
Industrial temperature range and drift
Operating from -40°C to 105°C, the TL1431AIDT covers the full industrial temperature band — a base-station PSU that sees 85°C internal ambient still has 20°C of margin before the reference hits its upper limit. Temperature coefficient is 100 ppm/°C typical, which translates to a 2.5 mV shift over a 100°C span at the 2.5 V nominal output — small enough that a 12-bit ADC with a 2.5 V reference sees less than 1 LSB of drift from the reference alone.
SOIC-8 surface-mount package for automated assembly
Housed in an 8-SOIC package (3.90 mm body width), the TL1431AIDT fits standard pick-and-place and reflow profiles — the same footprint as the industry-standard TL431 in SOIC-8, so a board laid out for that part accepts this one without a layout change. Available in Tape & Reel or Cut Tape options — the reel format suits volume production, while cut tape works for prototype runs and small-batch builds.
Active production and compliance status
RoHS3 compliant (2011/65/EU + 2015/863), with no restricted substances above the threshold — the part ships without a conflict-minerals or REACH exemption letter needed for EU-market equipment.