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Adjustable shunt regulator

TL431 Internal Circuitry

Explore the internal circuitry and functional stages of TL431.

Package view

Inside TL431

Reference, error amplifier and controlled shunt path.

Compact TL431 cutaway showing 2.495V reference, REF error amplifier and controlled current path from cathode to anode.
Functional architecture inside an original package drawing; not a physical die layout.

Explore the circuit

Select a stage to see its role and connections

Compare REF

The error amplifier compares REF against the internal reference.

Adjust cathode current

The output stage sinks more or less current from K to A.

Close an external loop

The external divider and feed resistor make that current regulate the output.

Component view