Precision shunt reference in a small footprint
The STMicroelectronics TS3431CILT is a shunt voltage reference with a ±0.25% initial tolerance, adjustable from 1.24 V up to 24 V via two external resistors. This puts it in the precision band for a three-terminal programmable reference — the 0.25% grade suits it for applications where a 1% or 2% part would eat into the system accuracy budget, such as A/D converter references or regulated power supply feedback loops. It sinks up to 100 mA cathode current with a minimum operating current of 500 µA, giving it a wide dynamic range for driving optocouplers or biasing error amplifiers in isolated supplies. The 100 ppm/°C temperature coefficient means the output voltage drifts 1 mV per 10 °C at a 1.24 V set point — stable enough for most industrial control loops without external trimming.