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TL431LI

ACTIVE

Adjustable precision shunt regulator with optimized reference current (pin layout: KRA)

Product details

VO (V) 2.495 Initial accuracy (max) (%) 0.5, 1 VO adj (min) (V) 2.495 VO adj (max) (V) 36 Iz for regulation (min) (µA) 400 Reference voltage (V) adjustable Rating Catalog Temp coeff (max) (ppm/°C) 63 Operating temperature range (°C) -40 to 125 Iout/Iz (max) (mA) 15
VO (V) 2.495 Initial accuracy (max) (%) 0.5, 1 VO adj (min) (V) 2.495 VO adj (max) (V) 36 Iz for regulation (min) (µA) 400 Reference voltage (V) adjustable Rating Catalog Temp coeff (max) (ppm/°C) 63 Operating temperature range (°C) -40 to 125 Iout/Iz (max) (mA) 15
SOT-23 (DBZ) 3 6.9204 mm² 2.92 x 2.37
  • Reference Voltage Tolerance at 25°C
    • 0.5% (B Grade)
    • 1% (A Grade)
  • Minimum Typical Output Voltage: 2.495 V
  • Adjustable Output Voltage: Vref to 36 V
  • Operation From −40°C to +125°C (Q Temp)
  • Maximum Temperature Drift
    • 10 mV (C Temp)
    • 17 mV (I Temp)
    • 27 mV (Q Temp)
  • 0.3-Ω Typical Output Impedance
  • Sink-Current Capability
    • Imin = 1 mA (max)
    • IKA = 15 mA (max)
  • Reference Input Current IREF: 0.4 µA (max)
  • Deviation of Reference Input Current over Temperature, II(dev): 0.3 µA (max)
  • Reference Voltage Tolerance at 25°C
    • 0.5% (B Grade)
    • 1% (A Grade)
  • Minimum Typical Output Voltage: 2.495 V
  • Adjustable Output Voltage: Vref to 36 V
  • Operation From −40°C to +125°C (Q Temp)
  • Maximum Temperature Drift
    • 10 mV (C Temp)
    • 17 mV (I Temp)
    • 27 mV (Q Temp)
  • 0.3-Ω Typical Output Impedance
  • Sink-Current Capability
    • Imin = 1 mA (max)
    • IKA = 15 mA (max)
  • Reference Input Current IREF: 0.4 µA (max)
  • Deviation of Reference Input Current over Temperature, II(dev): 0.3 µA (max)

The TL431LI device is a three-terminal adjustable shunt regulator, with specified thermal stability over applicable automotive, commercial, and military temperature ranges. The output voltage can be set to any value between Vref (approximately 2.495 V) and 36 V, with two external resistors. These devices have a typical output impedance of 0.3 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. This device is a pin-to-pin alternative to the industry standard TL431, with optimized Iref and IIdev performance. The lower Iref and IIdev values enable designers to achieve higher system accuracy and lower leakage current. The TL432LI device has exactly the same functionality and electrical specifications as the TL431LI device, but has a different pinout for the DBZ package.

The TL431LI device is offered in two grades, with initial tolerances (at 25°C) of 0.5% and 1%, for the B and A grade, respectively. In addition, low output drift versus temperature ensures good stability over the entire temperature range.

The TL43xLIxQ devices are characterized for operation from –40°C to 125°C.

The TL431LI device is a three-terminal adjustable shunt regulator, with specified thermal stability over applicable automotive, commercial, and military temperature ranges. The output voltage can be set to any value between Vref (approximately 2.495 V) and 36 V, with two external resistors. These devices have a typical output impedance of 0.3 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. This device is a pin-to-pin alternative to the industry standard TL431, with optimized Iref and IIdev performance. The lower Iref and IIdev values enable designers to achieve higher system accuracy and lower leakage current. The TL432LI device has exactly the same functionality and electrical specifications as the TL431LI device, but has a different pinout for the DBZ package.

The TL431LI device is offered in two grades, with initial tolerances (at 25°C) of 0.5% and 1%, for the B and A grade, respectively. In addition, low output drift versus temperature ensures good stability over the entire temperature range.

The TL43xLIxQ devices are characterized for operation from –40°C to 125°C.

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Technical documentation

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Type Title Date
* Data sheet TL431LI / TL432LI Programmable Shunt Regulator with Optimized Reference Current datasheet (Rev. A) PDF | HTML 12 Nov 2018
Application note Voltage Reference Selection and Design Tips For Data Converters (Rev. B) PDF | HTML 09 Jan 2024
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
Application note IEEE 802.3cg 10BASE-T1L Power over Data Lines Powered Device Design (Rev. A) PDF | HTML 02 Jun 2022
Application note Voltage and Processor Monitoring Solutions in Factory Automation and Control App (Rev. A) 05 Aug 2021
Analog Design Journal High-power, low-cost, discrete linear pre-regulator for automotive rear lights 21 Dec 2020
Application note Precision Current Sources and Sinks Using Voltage References 30 Jun 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
Application brief An Isolated 24 V Power Supply Window Monitor 01 Aug 2019
Application note Designing With the Improved TL431LI (Rev. A) 28 Jun 2019
E-book Voltage Supervisor and Reset ICs: Tips, Tricks and Basics 28 Jun 2019

Design & development

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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

TL431LI PSpice Transient Model

SLVMCW2.ZIP (56 KB) - PSpice Model
Simulation model

TL431LI Unencrypted PSpice Transient Model

SLVMCW1.ZIP (2 KB) - PSpice Model
Simulation model

TL431LI and ATL431LI PSpice Average Model

SLVMCX5.ZIP (78 KB) - PSpice Model
Simulation model

TL431LI and ATL431LI Unencrypted PSpice Average Model

SLVMCX4.ZIP (1 KB) - PSpice Model
Calculation tool

SHUNT-REFERENCE-CALC Shunt Reference Selector and Design Calculator

This tool guides the user through the design process for the TLx431 and LM40x0 family of shunt voltage references. This calculator will recommend resistance and capacitance values to optimally meet the user's desired specifications.
Supported products & hardware

Supported products & hardware

Products
Shunt voltage references
ATL431 2.5-V low-IQ adjustable precision shunt regulator ATL431LI Low-IQ programmable shunt regulator offered in an ultra-small DQN package ATL431LI-Q1 Automotive, high-bandwidth, low-IQ programmable shunt regulator (pinout: KRA) ATL432 2.5-V precision programmable shunt regulator ATL432LI High-bandwidth, low-IQ programmable shunt regulator (pinout: RKA) ATL432LI-Q1 Automotive, high-bandwidth, low-IQ programmable shunt regulator (pinout: RKA) 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 LM4040C25-EP Enhanced Product 2.5-V Precision Micropower Shunt Voltage Reference, 0.5% accuracy LM4041-N Fixed & adjustable, 45-µA, precision micropower shunt voltage reference LM4041-N-Q1 Automotive, precision micropower shunt voltage reference LM4041A12 1.2-V precision micropower shunt voltage reference with 0.1% accuracy LM4041B Adjustable, precision micropower shunt voltage reference with 0.2% accuracy LM4041B12 1.2-V precision micropower shunt voltage reference with 0.2% accuracy LM4041C Adjustable, precision micropower shunt voltage reference with 0.5% accuracy LM4041C12 1.2-V precision micropower shunt voltage reference with 0.5% accuracy LM4041D Adjustable, precision micropower shunt voltage reference with 1% accuracy LM4041D12 1.2-V precision micropower shunt voltage reference with 1% accuracy 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 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 TL431 Adjustable precision shunt regulator TL431-Q1 Automotive adjustable precision shunt regulator (pin layout: KRA) TL431C 2% adjustable precision shunt regulator TL431LI Adjustable precision shunt regulator with optimized reference current (pin layout: KRA) TL431LI-Q1 Automotive, adjustable, precision shunt regulator with optimized reference current TL432 Adjustable precision shunt regulator (reverse pinout) TL432-Q1 Automotive adjustable precision shunt regulator (pin layout: RKA) TL432LI Adjustable precision shunt regulator with optimized reference current (pin layout: RKA) TL432LI-Q1 Automotive, adjustable, precision shunt regulator with optimized reference current TLA431 All-capacitor stable precision programmable reference with KRA pin layout TLV431 1.5% accuracy, low-voltage, adjustable precision shunt regulator TLV431A 1% accuracy, low-voltage, adjustable precision shunt regulator TLV431A-Q1 Automotive, low-voltage adjustable precision shunt regulator TLV431B 0.5% accuracy, low-voltage, adjustable precision shunt regulator TLV431B-Q1 Automotive, low-voltage adjustable precision shunt regulator TLVH431 1.5% low-voltage wide-operating current adjustable precision shunt regulator TLVH431A 1% low-voltage wide-operating current adjustable precision shunt regulator TLVH431A-Q1 Automotive, low-voltage adjustable precision shunt regulator TLVH431B 0.5% low-voltage wide-operating current adjustable precision shunt regulator TLVH431B-EP Enhanced-plastic 0.5% low-voltage wide-operating-current adjustable precision shunt regulator TLVH431B-Q1 Automotive, low-voltage adjustable precision shunt regulator (reverse pinout) TLVH432 1.5% low-voltage wide-operating current adjustable precision shunt regulator (reverse pinout) TLVH432A 1% low-voltage wide-operating current adjustable precision shunt regulator (reverse pinout) TLVH432B 0.5% low-voltage wide-operating current adjustable precision shunt regulator (reverse pinout)
General-purpose op amps
TLV4313 Quad, 5.5-V, 1-MHz, low quiescent current (65-μA), RRIO operational amplifier TLV4314 Quad, 5.5-V, 3-MHz, RRIO operational amplifier TLV4314-Q1 Automotive-grade, quad, 5.5-V, 3-MHz, RRIO operational amplifier TLV4316 Quad, 5.5-V, 10-MHz, RRIO operational amplifier TLV4316-Q1 Automotive-grade, quad, 5.5-V, 10-MHz, RRIO operational amplifier TLV4379 Quad, 5.5-V, 90-kHz, low quiescent current (4-μA), RRIO operational amplifier
Precision op amps (Vos<1mV)
TLV4333 Quad, 350-kHz, low-noise, RRIO, CMOS operational amplifier for cost-sensitive systems TLV4376 Quad 5.5-MHz, 100-µV offset, 8-nV/√Hz noise, 815-µA power, precision operational amplifiers TLV4387 Quad, ultra-high-precision (10 μV) zero-drift (0.01 μV/°C) low-input-bias-current op amp
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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