SLVS543P August   2004  – November 2018 TL431 , TL432

PRODUCTION DATA.  

  1. Features
  2. Applications
    1.     Simplified Schematic
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
    1.     Pin Functions
  7. Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Thermal Information
    4. 7.4  Recommended Operating Conditions
    5. 7.5  Electrical Characteristics, TL431C, TL432C
    6. 7.6  Electrical Characteristics, TL431I, TL432I
    7. 7.7  Electrical Characteristics, TL431Q, TL432Q
    8. 7.8  Electrical Characteristics, TL431AC, TL432AC
    9. 7.9  Electrical Characteristics, TL431AI, TL432AI
    10. 7.10 Electrical Characteristics, TL431AQ, TL432AQ
    11. 7.11 Electrical Characteristics, TL431BC, TL432BC
    12. 7.12 Electrical Characteristics, TL431BI, TL432BI
    13. 7.13 Electrical Characteristics, TL431BQ, TL432BQ
    14. 7.14 Typical Characteristics
  8. Parameter Measurement Information
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
    4. 9.4 Device Functional Modes
      1. 9.4.1 Open Loop (Comparator)
      2. 9.4.2 Closed Loop
  10. 10Applications and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Comparator With Integrated Reference
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Basic Operation
            1. 10.2.1.2.1.1 Overdrive
          2. 10.2.1.2.2 Output Voltage and Logic Input Level
            1. 10.2.1.2.2.1 Input Resistance
        3. 10.2.1.3 Application Curve
      2. 10.2.2 Shunt Regulator/Reference
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
          1. 10.2.2.2.1 Programming Output/Cathode Voltage
          2. 10.2.2.2.2 Total Accuracy
          3. 10.2.2.2.3 Stability
          4. 10.2.2.2.4 Start-Up Time
        3. 10.2.2.3 Application Curve
    3. 10.3 System Examples
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Nomenclature
    2. 13.2 Related Links
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Community Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

Overdrive

Slow or inaccurate responses can also occur when the reference pin is not provided enough overdrive voltage. This is the amount of voltage that is higher than the internal virtual reference. The internal virtual reference voltage will be within the range of 2.5 V ±(0.5%, 1.0% or 1.5%) depending on which version is being used. The more overdrive voltage provided, the faster the TL431 will respond.

For applications where TL431 is being used as a comparator, it is best to set the trip point to greater than the positive expected error (i.e. +1.0% for the A version). For fast response, setting the trip point to >10% of the internal VREF should suffice.

For minimal voltage drop or difference from Vin to the ref pin, it is recommended to use an input resistor <10kΩ to provide Iref.