TL431 PDF – Adjustable Shunt Regulator – TI

This is three-terminal adjustable shunt regulator.

Part Number: TL431

Function : Adjustable Precision Shunt Regulator

Package: SOIC 8 Pin , DIP 8 Pin, SOT23-3 Type

Manufacturer: Texas Instruments


TL431 pdf datasheet


This is a three-terminal adjustable shunt regulator, also known as a programmable zener diode, that can provide stable and accurate voltage reference and regulation. While it may look similar to a diode in some packages, it functions differently by regulating the voltage between its reference and cathode terminals using an internal voltage comparator and feedback loop. It is a type of integrated circuit and has an integrated reference voltage source, which is used to set the output voltage using external resistors.

The TL432 and TL431 devices are three-terminal adjustable shunt regulators, with specified thermal stability over applicable automotive, commercial, and military temperature ranges. The output voltage can be set to any value between Vref (approximately 2.5 V) and 36 V, with two external resistors.

These devices have a typical output impedance of 0.2 Ω. Active output circuitry provides a very sharp turn-on characteristic, making these devices excellent replacements for Zener diodes in many applications, such as onboard regulation, adjustable power supplies, and switching power supplies.


TL431 pinout


1. Three-terminal adjustable shunt regulator
2. Adjustable output voltage
3. Wide operating voltage range
4. Low output impedance
5. High stability and accuracy
6. Low power consumption
7. Available in various packages

Official Site :


1. Adjustable voltage and current referencing

2. Secondary side regulation in flyback SMPSs

3. Zener replacement

4. Voltage monitoring

5. Comparator with integrated reference


Parts similar:

1. LM431: A similar three-terminal adjustable shunt regulator with slightly different specifications.

2. Precision voltage regulators, such as LM317 and LM7805, do not require external resistors to set the output voltage, which can simplify the circuit design. They also have higher current handling capability and better performance in terms of temperature stability and output noise. However, they may be more expensive than TL431 and have higher power consumption.

FAQs about related this parts:

1. Can LM431 be used as a drop-in replacement for this IC?
Yes, LM431 is a similar device to TL431 and can be used as a drop-in replacement in most applications. However, it may have slightly different specifications and performance characteristics.

2. How do zener diodes compare to TL431 as a voltage reference device?
Zener diodes can provide a stable reference voltage, but they do not have adjustable output voltage like TL431. They are also less precise and may have a higher output impedance.

Other data sheets are available within the file: TL431ACLP, TL431ACLPE3

TL431 Datasheet PDF

TL431 pdf


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