Industrial-grade shunt reference in a compact SOT-323
The TL431ICT is an adjustable shunt voltage reference from STMicroelectronics, part of the industry-standard TL431 family. It provides a programmable output from 2.495 V up to 36 V by selecting two external resistors, with a typical output impedance of 0.2 Ω. Rated for continuous cathode current up to 100 mA and a minimum cathode current of 1 mA, it suits both precision voltage regulation and series-pass regulator biasing in industrial power supplies, battery chargers, and isolated feedback loops.
Reference tolerance and output range — what they drive
With a maximum output of 36 V, the part can regulate rails in 24 V industrial buses and 28 V avionics supplies without an external clamp. The shunt topology means it sinks current from the supply rail through a bias resistor, so the load current plus the 1 mA cathode minimum must fit within the resistor's current budget.
Package and footprint for production
Supplied in a 6-lead SOT-323-6L (SC-88 equivalent) surface-mount package, the TL431ICT occupies roughly 2.0 mm × 2.1 mm of board area — suitable for dense mixed-signal boards where every square millimetre counts. The SOT-323 lead pitch is 0.65 mm, compatible with standard reflow profiles and visual inspection.