Adjustable shunt reference for feedback and biasing
It sets an output voltage anywhere from a 2.495 V minimum up to 36 V maximum using two external resistors, making it a standard building block for power-supply feedback loops, precision current limiting, and voltage monitoring circuits.
The 100 mA cathode current capability is enough to drive the optocoupler LED in a secondary-side feedback loop directly, without an extra buffer transistor. The 1 mA minimum cathode current means the reference stays in regulation even at light load — relevant when the feedback divider draws minimal current. At ±2.2% tolerance on the 2.495 V internal reference, the output voltage will vary by roughly ±55 mV at the nominal set point. That is adequate for standard 5 V or 3.3 V rail regulation but too loose for precision analog supplies where a ±0.5% or ±1% grade TL431 variant would be specified.
Procurement for this order code goes through independent distribution — surplus stock, new-old-stock, or broker channels. The SOT-23-5 package (SC-74A case) is a common footprint shared by many active shunt reference parts, so if a BOM line needs a drop-in replacement, the pin-compatible TL432 family siblings in the same package are the natural cross-shop candidates. No single official replacement is designated by TI.