Adjustable shunt reference for feedback and biasing
It provides a 2.495V reference between the cathode and anode when the reference pin is tied to the cathode, with the output voltage set by two external resistors to any value up to 36 V. For a 5 V rail set with a 2.495V reference and a 1:1 divider, the output stays within 50 mV of target at 25°C before temperature drift. The 100 mA cathode current capability drives the optocoupler LED in an isolated flyback supply or sinks the feedback node of a linear regulator. The 700 µA minimum cathode current ensures the reference stays in regulation at light load.
It does not carry an automotive-grade rating, so it is not specified for under-hood or chassis-mounted applications where AEC-Q100 qualification is required. The SOT-89-3 package (TO-243AA) has a large collector tab on the cathode pin that doubles as a thermal path. In a typical feedback application dissipating under 50 mW, the junction temperature stays well within the operating range with standard FR-4 copper area.
The base product number TL432 spans multiple tolerance and package variants, so the BOM should specify the full TL432AIPK to lock in the ±1% grade and SOT-89-3 footprint.