Home Power management Voltage references Shunt voltage references

ATL431

ACTIVE

2.5-V low-IQ adjustable precision shunt regulator

A newer version of this product is available

open-in-new Compare alternates
Pin-for-pin with same functionality to the compared device
ATL431LI ACTIVE Low-IQ programmable shunt regulator offered in an ultra-small DQN package This pin-to-pin upgrade offers improved stability boundaries and lower reference input current to optimize voltage-output accuracy.
Same functionality with different pin-out to the compared device
TL431 ACTIVE Adjustable precision shunt regulator for cost optimized designs

Product details

VO (V) 2.5 Initial accuracy (max) (%) 0.5, 1 VO adj (min) (V) 2.5 VO adj (max) (V) 36 Iz for regulation (min) (µA) 20 Reference voltage (V) adjustable Rating Catalog Temp coeff (max) (ppm/°C) 92 Operating temperature range (°C) -40 to 125 Iout/Iz (max) (mA) 100
VO (V) 2.5 Initial accuracy (max) (%) 0.5, 1 VO adj (min) (V) 2.5 VO adj (max) (V) 36 Iz for regulation (min) (µA) 20 Reference voltage (V) adjustable Rating Catalog Temp coeff (max) (ppm/°C) 92 Operating temperature range (°C) -40 to 125 Iout/Iz (max) (mA) 100
SOT-23 (DBZ) 3 6.9204 mm² 2.92 x 2.37
  • Adjustable Regulated Output of 2.5 V to 36 V
  • Very-Low Operating Current
    • IKA(min) = 35 µA (Max)
    • IREF = 150 nA (Max)
  • Internally Compensated for Stability
    • Stable With No Capacitive Load
  • Reference Voltage Tolerances at 25°C
    • 0.5% for B Grade
    • 1% for A Grade
  • Typical Temperature Drift
    • 5 mV (–40°C to +85°C); I Version
    • 6 mV (–40°C to +125°C); Q Version
  • Extended Cathode Current Range 35 µA to 100 mA
  • Low Output Impedance of 0.3 Ω (Max)
  • Adjustable Regulated Output of 2.5 V to 36 V
  • Very-Low Operating Current
    • IKA(min) = 35 µA (Max)
    • IREF = 150 nA (Max)
  • Internally Compensated for Stability
    • Stable With No Capacitive Load
  • Reference Voltage Tolerances at 25°C
    • 0.5% for B Grade
    • 1% for A Grade
  • Typical Temperature Drift
    • 5 mV (–40°C to +85°C); I Version
    • 6 mV (–40°C to +125°C); Q Version
  • Extended Cathode Current Range 35 µA to 100 mA
  • Low Output Impedance of 0.3 Ω (Max)

The ATL431 and ATL432 are three-terminal adjustable shunt regulators, with specified thermal stability over applicable automotive, commercial, and industrial 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 0.05 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.

The ATL43x has > 20x improvement cathode current range over it’s TL43x predecessor. It also is stable with a wider range of load capacitance types and values.

ATL431 and ATL432 are the exact same parts but with different pinouts and order numbers. The ATL43x is offered in two grades, with initial tolerances (at 25°C) of 0.5%, 1%, for the B and A grade, respectively. In addition, low output drift vs temperature ensures consistent voltage regulation over the entire temperature range.

The ATL43xxI devices are characterized for operation from –40°C to +85°C, and the ATL43xxQ devices are characterized for operation from –40°C to +125°C.

The ATL431 and ATL432 are three-terminal adjustable shunt regulators, with specified thermal stability over applicable automotive, commercial, and industrial 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 0.05 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.

The ATL43x has > 20x improvement cathode current range over it’s TL43x predecessor. It also is stable with a wider range of load capacitance types and values.

ATL431 and ATL432 are the exact same parts but with different pinouts and order numbers. The ATL43x is offered in two grades, with initial tolerances (at 25°C) of 0.5%, 1%, for the B and A grade, respectively. In addition, low output drift vs temperature ensures consistent voltage regulation over the entire temperature range.

The ATL43xxI devices are characterized for operation from –40°C to +85°C, and the ATL43xxQ devices are characterized for operation from –40°C to +125°C.

Download View video with transcript Video

Technical documentation

star =Top documentation for this product selected by TI
No results found. Please clear your search and try again.
View all 19
Type Title Date
* Data sheet ATL431, ATL432 2.5-V Low Iq Adjustable Precision Shunt Regulator datasheet (Rev. D) PDF | HTML 20 Oct 2016
Application note Optimization of a Shunt Reference for Flyback Converters PDF | HTML 18 Oct 2023
Application note Designing Stable Isolated Power Supplies with Shunt Regulators PDF | HTML 29 Dec 2022
E-book Tips and tricks for designing with voltage references (Rev. A) 07 May 2021
Analog Design Journal High-power, low-cost, discrete linear pre-regulator for automotive rear lights 21 Dec 2020
White paper Simplifying Signal Chain Design for High Performance in Small Systems 22 Oct 2020
Technical article How modern voltage references help shrink small designs PDF | HTML 01 Jun 2020
Application note Using the TL431 for Undervoltage and Overvoltage Detection (Rev. A) 11 Dec 2019
Selection guide 431 Device Nomenclature (Rev. B) 18 Sep 2019
E-book Voltage Supervisor and Reset ICs: Tips, Tricks and Basics 28 Jun 2019
Application note Diode-Based Temperature Measurements (Rev. A) 17 May 2019
Technical article How to use a voltage reference as a voltage regulator PDF | HTML 04 Dec 2018
Technical article The great compromise: voltage references PDF | HTML 07 Dec 2015
Technical article Designing for isolated DC/DC converter shunt safety PDF | HTML 29 Aug 2015
Technical article Can overcurrent protection be simple and precise, while minimizing cost? PDF | HTML 31 Jul 2015
Technical article How to get no-load power savings in AC to DC supplies PDF | HTML 08 Jun 2015
EVM User's guide ATL431EVM User's Guide 28 Apr 2015
Application note Designing with the Advanced TL431, ATL431 08 Jan 2015
Application note Designing Overcurrent protection for TPL7407L Peripheral Driver 05 Nov 2014

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
Evaluation board

UCC28780EVM-002 — UCC28780 active clamp flyback 45W AC/DC EVM with GaN FET

The UCC28780EVM-002 demonstrates high-efficiency and high-density for a 45-W off-line adapter using the UCC28780 active-clamp flyback controller at high frequency nominal 300 kHz using GaN MOSFET Power ICs, NV6115 and NV6117.  The EVM also uses the UCC24612 synchronous rectifier controller on (...)

User guide: PDF
Not available on TI.com
Evaluation board

UCC28780EVM-021 — UCC28780 active clamp flyback converter 45W EVM with UCC24612 and Si MOSFET

The UCC28780EVM-021 is a 45-W evaluation module (EVM) for evaluating an off-line active-clamp flyback adapter for notebook charging and other applications. The EVM meets CoC Tier 2 and DoE Level 6 efficiency requirements. It is intended for evaluation purposes and is not intended to be an end (...)

User guide: PDF
Not available on TI.com
Evaluation board

UCC28781EVM-053 — UCC28781-Q1 evaluation module for automotive 500-Vdc input ZVS-flyback power supply applications

UCC28781EMV-053 demonstrates high-efficiency, high-density, high-voltage automotive bias supply with 60-W , 15-V ouput using a zero-voltage-switching flyback (ZVSF) controller. The UCC28781-Q1 drives a primary-side silicon MOSFET directly and drives a secondary-side synchronous rectifier through (...)

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

ATL431A PSpice Transient Model (Rev. D)

SLVMAT0D.ZIP (51 KB) - PSpice Model
Simulation model

ATL431A TINA-TI TRANSIENT REFERENCE DESIGN

SLVMD61.TSC (753 KB) - TINA-TI Reference Design
Simulation model

ATL431A TINA-TI TRANSIENT SPICE MODEL

SLVMD60.ZIP (8 KB) - TINA-TI Spice Model
Simulation model

ATL431A Unencrypted PSpice Transient Model (Rev. B)

SLVMBJ2B.ZIP (2 KB) - PSpice Model
Simulation model

ATL431B PSpice Transient Model (Rev. C)

SLVMAS9C.ZIP (58 KB) - PSpice Model
Simulation model

ATL431B Unencrypted PSpice Transient Model

SLVMBN7.ZIP (1 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 (...)

Many TI reference designs include the ATL431

Use our reference design selection tool to review and identify designs that best match your application and parameters.

Package Pins Download
SOT-23 (DBZ) 3 View options

Ordering & quality

Information included:
  • RoHS
  • REACH
  • Device marking
  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
  • Material content
  • Qualification summary
  • Ongoing reliability monitoring
Information included:
  • Fab location
  • Assembly location

Support & training

TI E2E™ forums with technical support from TI engineers

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​​​​​​​

Videos