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LM431

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2%, 1%, or 0.5% accuracy, adjustable precision Zener shunt regulator

Product details

VO (V) 2.5 Initial accuracy (max) (%) 0.5, 1, 2 VO adj (min) (V) 2.5 VO adj (max) (V) 36 Iz for regulation (min) (µA) 400 Reference voltage (V) adjustable Rating Catalog Temp coeff (max) (ppm/°C) 97 Operating temperature range (°C) -40 to 85 Iout/Iz (max) (mA) 100
VO (V) 2.5 Initial accuracy (max) (%) 0.5, 1, 2 VO adj (min) (V) 2.5 VO adj (max) (V) 36 Iz for regulation (min) (µA) 400 Reference voltage (V) adjustable Rating Catalog Temp coeff (max) (ppm/°C) 97 Operating temperature range (°C) -40 to 85 Iout/Iz (max) (mA) 100
SOIC (D) 8 29.4 mm² 4.9 x 6 SOT-23 (DBZ) 3 6.9204 mm² 2.92 x 2.37 TO-92 (LP) 3 19.136 mm² 5.2 x 3.68
  • Average Temperature Coefficient 50 ppm/°C
  • Temperature Compensated for Operation Over
    the Full Temperature Range
  • Programmable Output Voltage
  • Fast Turnon Response
  • Low-Output Noise
  • Low-Dynamic Output Impedance
  • Available in Space-Saving SOIC-8, SOT-23, and
    TO-92 Packages
  • Average Temperature Coefficient 50 ppm/°C
  • Temperature Compensated for Operation Over
    the Full Temperature Range
  • Programmable Output Voltage
  • Fast Turnon Response
  • Low-Output Noise
  • Low-Dynamic Output Impedance
  • Available in Space-Saving SOIC-8, SOT-23, and
    TO-92 Packages

The LM431 is a 3-terminal adjustable shunt regulator with ensured temperature stability over the entire temperature range of operation. The output voltage may be set at any level greater than 2.5 V (VREF) up to 36 V merely by selecting two external resistors that act as a voltage divided network. Due to the sharp turnon characteristics this device is an excellent replacement for many Zener diode applications.

The LM431 is available in space-saving SOIC-8, SOT-23, and TO-92 packages.

The LM431 is a 3-terminal adjustable shunt regulator with ensured temperature stability over the entire temperature range of operation. The output voltage may be set at any level greater than 2.5 V (VREF) up to 36 V merely by selecting two external resistors that act as a voltage divided network. Due to the sharp turnon characteristics this device is an excellent replacement for many Zener diode applications.

The LM431 is available in space-saving SOIC-8, SOT-23, and TO-92 packages.

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Technical documentation

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Type Title Date
* Data sheet LM431 Adjustable Precision Zener Shunt Regulator datasheet (Rev. H) PDF | HTML 06 Jan 2016
Application brief A Simple Constant Voltage Regulation Using the MODE Pin (Rev. A) PDF | HTML 15 Feb 2024
E-book Tips and tricks for designing with voltage references (Rev. A) 07 May 2021
Selection guide 431 Device Nomenclature (Rev. B) 18 Sep 2019
E-book Voltage Supervisor and Reset ICs: Tips, Tricks and Basics 28 Jun 2019
Analog Design Journal Low-cost flyback solutions for 10-mW standby power 22 Jan 2014
Application note AN-2102 LM3464 and LM5021 DHC 25W Reference Designs (Rev. A) 01 May 2013
Application note Precision Output Current Limiting Using Average Current Monitor Feature 21 Jun 2011
Application note TO-92 Packing Options / Ordering Instructions (Rev. A) 23 Jun 2010

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

ATL431EVM-001 — ATL431 adjustable shunt regulator evaluation module

The ATL431EVM-001 evaluation module (EVM) features the functionality and adjustability of the ATL431 by letting you program the cathode voltage with various resistor values. You can also set the cathode current using the various resistors in series with the supply. (...)

User guide: PDF
Not available on TI.com
Simulation model

LM431 Unencrypted PSpice Transient Model Package (Rev. A)

SNVMAB5A.ZIP (49 KB) - PSpice Model
Calculation tool

SHUNT_VOLTAGE_REFERENCE_RESISTOR_CALCULATOR Shunt Voltage Reference External Resistor Quick Start Calculator

This external resistor quick-start calculator tool lets you easily calculate valid external resistor values relative to voltage reference, supply and load-current bounds. With these inputs, you can instantly view the resulting calculations and use the color-coded indications to understand (...)

Supported products & hardware

Supported products & hardware

Products
Die & wafer services
LM336-2.5-MIL Shunt Voltage Reference
Shunt voltage references
ATL431 2.5-V low-IQ adjustable precision shunt regulator LM136-2.5-N Voltage Reference Diode LM136-5.0 5.0V Reference Diode LM136-5.0QML 5.0V Reference Diode LM136A-2.5QML 2.5V Reference Diode LM136A-2.5QML-SP Radiation-hardened QMLV, 2.5-V shunt voltage reference LM136A-5.0QML 5.0V Reference Diode LM185-1.2-N Micropower Voltage Reference Diode LM185-1.2QML Micropower Voltage Reference Diode LM185-1.2QML-SP Radiation-hardened QMLV, 1.2-V shunt voltage reference LM185-2.5-N Micropower Voltage Reference Diode LM185-2.5QML Micropower Voltage Reference Diode LM185-2.5QML-SP Space-grade QMLV 2.5-V  shunt voltage reference LM185-ADJ Adjustable Micropower Voltage Reference LM185QML Adjustable Micropower Voltage Reference LM285-1.2 1.235-V, –40°C to +85°C, micropower voltage reference LM285-1.2-N 1.235-V, –40°C to +85°C, micropower voltage reference diode LM285-2.5 2.5-V, –40°C to +85°C, micropower voltage reference LM285-2.5-N 2.5-V, –40°C to +85°C, micropower voltage reference diode LM285-ADJ Adjustable, 85°C, micropower voltage reference LM336-2.5 0°C to 70°C, 2.5-V integrated reference circuit LM336-2.5-N Voltage reference diode LM336-5.0 5-V reference diode LM385-1.2 1.235-V, 2%, 0°C to 70°C, micropower voltage reference LM385-1.2-MIL Micropower Voltage Reference LM385-1.2-N 1.235-V, 0°C to 70°C, micropower voltage reference diode LM385-2.5 2.5-V, 2%, 70°C, micropower voltage reference LM385-2.5-N 2.5-V, 0°C to 70°C, micropower voltage reference diode LM385-ADJ Adjustable, 70°C, micropower voltage reference LM4030 Ultra-high-precision shunt voltage reference LM4040 Fixed voltage, 45-µA, precision micropower shunt voltage reference LM4040-N 100-ppm/°C precision micropower shunt voltage reference LM4040-N-Q1 Automotive, 100-ppm/°C precision micropower shunt voltage reference LM4041-N Fixed & adjustable, 45-µA, precision micropower shunt voltage reference LM4041-N-Q1 Automotive, precision micropower shunt voltage reference LM4050-N 50-ppm/°C precision micropower shunt voltage reference LM4050-N-Q1 Automotive, 50-ppm/°C precision micropower shunt voltage reference LM4050QML-SP Radiation-hardened QMLV, 2.5-V or 5-V shunt voltage reference LM4051-N Fixed & adjustable, precision micropower shunt voltage reference LM431 2%, 1%, or 0.5% accuracy, adjustable precision Zener shunt regulator LM4431 Micropower shunt voltage reference LMV431 1.5%, low-voltage (1.24-V) adjustable precision shunt regulator LMV431A 1%, low-voltage (1.24-V) adjustable precision shunt regulator LMV431B 0.5%, low-voltage (1.24-V) adjustable precision shunt regulator
Current references
LM134 3-Terminal Adjustable Current Source LM234 100°C 3-pin adjustable current source LM334 0°C to 70°C 3-pin adjustable current source
Simulation tool

PSPICE-FOR-TI — PSpice® for TI design and simulation tool

PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)

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Package Pins Download
SOIC (D) 8 View options
SOT-23 (DBZ) 3 View options
TO-92 (LP) 3 View options

Ordering & quality

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