on November 10th 76

Why the TL431A is Ideal for Precision Voltage Regulation

The TL431A is a versatile and programmable voltage reference regulator, ideal for circuits needing stable and adjustable voltage control. This article covers its features, applications, and specifications to help you understand how it can enhance your circuit designs.

Catalog

TL431A Product Overview

The TL431 is a versatile three-terminal programmable shunt regulator. Designed to function as a low-temperature coefficient zener diode, it allows for easy voltage regulation with just two external resistors. You can adjust its voltage from Vref up to 36V, making it adaptable to a variety of applications. The TL431A is also known for its wide operating current range, spanning from 1.0 mA to 100 mA, which adds to its flexibility in different circuit setups. With a typical dynamic impedance of 0.22 Ω, this device provides consistent performance across various conditions.

TL431A Pin Configuration

TL431A CAD Model

TL431A Symbol

TL431A Footprint

TL431A 3D Model

TL431A Key Features

Programmable Output Voltage

With the TL431A, you can set the output voltage up to 36V by adjusting the values of two external resistors. This flexibility allows you to tailor it to your specific circuit requirements, making it ideal for various applications.

Precise Voltage Reference

This device provides reliable voltage reference tolerance at ±0.4% (typically at 25°C for the TL431B variant). This precision enhances its performance in circuits that rely on stable voltage levels, giving you dependable results.

Low Output Impedance

The TL431A has a low dynamic output impedance of around 0.22 Ω. This low impedance contributes to a stable output, helping it to maintain consistent performance across different operating conditions.

Wide Current Range

Supporting a current range of 1.0 mA to 100 mA, the TL431A can handle varied loads, adding versatility to its use in applications where different current levels are needed.

Temperature Compensation

The TL431A is designed to function effectively across a broad temperature range. This temperature compensation ensures that the device maintains its performance even as environmental conditions change, making it dependable in diverse settings.

Low Noise Output

With a low output noise voltage, the TL431A helps reduce interference, providing you with a cleaner signal in noise-sensitive applications.

Automotive Grade

For those applications that demand reliability, the TL431A meets AEC-Q100 standards, meaning it’s suited for automotive use and other areas requiring stable, consistent performance.

TL431A Performance Advantages

This device is an excellent choice for replacing traditional zener diodes, especially in circuits that demand a stable reference. Its 2.5V reference voltage offers dependable precision, which works well with standard 5.0V logic supplies, allowing it to provide a consistent reference voltage. The TL431A can function effectively as either a positive or negative voltage reference, expanding its usage potential. Due to its design, it maintains stability across various operating currents and load capacitances, making it reliable for applications such as digital voltmeters, power supplies, and operational amplifier circuits.

TL431A Specifications

Technical specifications, features, characteristics, and components with comparable specifications of ON Semiconductor TL431A

Type	Parameter
Lifecycle Status	ACTIVE (Last Updated: 1 day ago)
Factory Lead Time	2 Weeks
Mounting Type	Surface Mount
Package / Case	8-SOIC (0.154, 3.90mm Width)
Number of Pins	8
Operating Temperature	0°C ~ 70°C TA
Packaging	Tube
Published	2005
Tolerance	±1%
JESD-609 Code	e3
Pbfree Code	Yes
Part Status	Active
Moisture Sensitivity Level (MSL)	1 (Unlimited)
Number of Terminations	8
ECCN Code	EAR99
Temperature Coefficient	50ppm/°C Typical
Terminal Finish	Tin (Sn)
Terminal Position	DUAL
Terminal Form	GULL WING
Peak Reflow Temperature (°C)	260
Number of Functions	1
Terminal Pitch	1.27mm
Current Rating	100mA
Time@Peak Reflow Temperature-Max (s)	40
Base Part Number	TL431
Pin Count	8
Number of Outputs	1
Output Voltage	36V
Output Type	Adjustable
Max Output Current	100mA
Trim/Adjustable Output	YES
Analog IC - Other Type	THREE TERMINAL VOLTAGE REFERENCE
Accuracy	1 %
Max Output Voltage	36V
Voltage - Output (Min/Fixed)	2.495V
Max Input Voltage	37V
Halogen Free	Halogen Free
Reference Voltage	36V
Reference Type	Shunt
Min Output Voltage	2.495V
Current - Cathode	1mA
Height	1.5mm
Length	5mm
Width	4mm
REACH SVHC	No SVHC
Radiation Hardening	No
RoHS Status	ROHS3 Compliant
Lead Free	Lead Free

TL431A Functional Diagram

TL431A Representative Block Diagram

TL431A Representative Schematic Diagram

Simplified Model of TL431A Device

Parts with Similar Specifications to TL431A

The parts listed have specifications similar to the ON Semiconductor TL431A

Specification	TL431ACDG	TL431AIYDT	TL431ACDR2G	TL431AIDG	TL431AIDR2G
Manufacturer	ON Semiconductor	STMicroelectronics	ON Semiconductor	ON Semiconductor	ON Semiconductor
Package / Case	8-SOIC (0.154, 3.90mm Width)	8-SOIC (0.154, 3.90mm Width)	8-SOIC (0.154, 3.90mm Width)	8-SOIC (0.154, 3.90mm Width)	8-SOIC (0.154, 3.90mm Width)
Number of Pins	8	8	8	8	8
Max Output Current	100 mA	100 mA	100 mA	100 mA	100 mA
Max Input Voltage	37 V	37 V	37 V	37 V	37 V
Min Output Voltage	2.495 V	2.495 V	2.495 V	2.495 V	2.495 V
Output Voltage	36 V	36 V	36 V	36 V	36 V
Max Output Voltage	36 V	36 V	36 V	36 V	36 V
Tolerance	±1%	±1%	±1%	±1%	±1%
Temperature Coefficient	50ppm/°C Typical	50ppm/°C Typical	50ppm/°C Typical	50ppm/°C Typical

Equivalents of TL431A

Model Number	Manufacturer	Description
TL431CLPRP	Motorola Mobility LLC	1-OUTPUT THREE TERM VOLTAGE REFERENCE, 2.495V, PBCY3
TL431AIDR2G	Rochester Electronics LLC	Three Terminal Voltage Reference, 1 Output, 2.495V, Trim/Adjustable, BIPolar, PDSO8, LEAD FREE, PLASTIC, SOIC-8
TL431IYDT	STMicroelectronics	Programmable Voltage Reference
TL431AILPM	Texas Instruments	Adjustable precision shunt regulator 3-TO-92 -40 to 85
TL431ACLPRX	Fairchild Semiconductor Corp.	Three Terminal Voltage Reference, 1 Output, 2.495V, Trim/Adjustable, BIPolar, PBCY3, TO-92, 3 PIN
TL431IDRG4	Texas Instruments	Adjustable precision shunt regulator 8-SOIC -40 to 85
TL431ACDR2	Freescale Semiconductor	IC,VOLT REGULATOR,ADJUSTABLE,+2.5 TO +36V,BIPOLAR,SOP,8PIN,PLASTIC
TL431CLPR	Rochester Electronics LLC	Three Terminal Voltage Reference, 1 Output, 2.495V, Trim/Adjustable, BIPolar, PBCY3, ROHS COMPLIANT, PLASTIC, TO-226, TO-92, 3 PIN
TL431CLPM	Rochester Electronics LLC	Three Terminal Voltage Reference, 1 Output, 2.495V, Trim/Adjustable, BIPolar, PBCY3, ROHS COMPLIANT, PLASTIC, TO-226, TO-92, 3 PIN
TL431CLPB-TDJ	Texas Instruments	Adjustable Precision Shunt Regulator 3-TO-92 0 to 75

TL431A Applications

Shunt Regulator

Used as a shunt regulator, the TL431A helps stabilize the voltage across a load by diverting excess current. This application is common in circuits requiring a constant voltage, as it helps ensure that any variations in the current supply won’t affect the voltage levels. Shunt regulation is beneficial in maintaining circuit stability, especially in applications with varying load demands.

High Current Shunt Regulator

For circuits with high current requirements, the TL431A can handle larger loads effectively, acting as a high-current shunt regulator. This capability is valuable when a steady voltage is needed in high-demand environments. The device manages high current levels without compromising on stability, making it a solid choice for industrial and power supply applications.

Series Pass Regulator

The TL431A can function as a series pass regulator, controlling output voltage by adjusting the current flowing through it. In this configuration, it helps maintain a stable voltage in the output by responding to variations in load and input voltage. This feature is particularly useful in applications where precise voltage regulation is required to prevent fluctuations.

TRIAC Crowbar Circuit

In a TRIAC crowbar circuit, the TL431A provides over-voltage protection by redirecting excess voltage away from sensitive components. When the voltage exceeds a safe level, the device engages the TRIAC, helping protect the circuit from potential damage. This is especially useful in power supplies and other critical applications where sudden voltage spikes need to be controlled.

SRC Crowbar Circuit

Similar to the TRIAC crowbar, the TL431A can be used in an SRC crowbar circuit to protect against over-voltage conditions. By controlling the SRC, it helps safeguard components from voltage surges, ensuring the integrity and durability of the circuit. This application is ideal for environments with unpredictable voltage levels where protection against sudden increases is necessary.

Voltage Monitoring

The TL431A also works well in voltage monitoring circuits, where it provides a stable reference voltage that can trigger alerts or adjustments when voltage levels deviate from the norm. This is especially valuable in systems that need to operate within specific voltage ranges to ensure performance and safety, such as battery-powered devices and regulated power supplies.

Linear Ohmmeter

In linear ohmmeter applications, the TL431A offers a stable voltage reference, helping to accurately measure resistance. It enables precise readings by maintaining a consistent voltage across the resistor being measured. This application is beneficial for diagnostic equipment and other tools requiring reliable resistance measurements.

Phono Amplifier Reference

For audio circuits, the TL431A serves as a stable reference in phono amplifiers, enhancing sound quality by minimizing interference. In this application, the device ensures that the amplifier provides clear, consistent output, contributing to better audio fidelity. This makes it useful in various audio setups where maintaining signal purity is a priority.

TL431A Package Information

TL431A Manufacturer

ON Semiconductor, listed as Nasdaq: ON, is committed to energy-saving solutions with an extensive product portfolio focused on power and signal management technologies. The company’s offerings are recognized for their quality and efficiency, which are delivered through a well-structured global supply chain. With operations across North America, Europe, and the Asia Pacific, ON Semiconductor provides a reliable and responsive service that aligns well with the demands of modern markets.

Datasheet PDF

TL431IYDT Datasheet:

TL431IYDT.pdf

TL431ACDG Datasheet:

TL431ACDG.pdf

TL431ACDG.pdf

TL431AIYDT Datasheet:

TL431AIYDT.pdf

TL431ACDR2G Datasheet:

TL431ACDR2G.pdf

TL431ACDR2G.pdf

TL431AIDG Datasheet:

TL431AIDG.pdf

TL431AIDG.pdf

TL431AIDR2G Datasheet:

TL431AIDR2G.pdf

TL431AIDR2G.pdf