SLVS543S August   2004  – May 2024 TL431 , TL432

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Thermal Information
    4. 6.4  Recommended Operating Conditions
    5. 6.5  Electrical Characteristics, TL431C, TL432C
    6. 6.6  Electrical Characteristics, TL431I, TL432I
    7. 6.7  Electrical Characteristics, TL431Q, TL432Q
    8. 6.8  Electrical Characteristics, TL431AC, TL432AC
    9. 6.9  Electrical Characteristics, TL431AI, TL432AI
    10. 6.10 Electrical Characteristics, TL431AQ, TL432AQ
    11. 6.11 Electrical Characteristics, TL431BC, TL432BC
    12. 6.12 Electrical Characteristics, TL431BI, TL432BI
    13. 6.13 Electrical Characteristics, TL431BQ, TL432BQ
    14. 6.14 Typical Characteristics
  8. 7 Parameter Measurement Information
    1. 7.1 Temperature Coefficient
    2. 7.2 Dynamic Impedance
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
      1. 8.4.1 Open Loop (Comparator)
      2. 8.4.2 Closed Loop
  10. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Comparator With Integrated Reference
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Basic Operation
            1. 9.2.1.2.1.1 Overdrive
          2. 9.2.1.2.2 Output Voltage and Logic Input Level
            1. 9.2.1.2.2.1 Input Resistance
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Shunt Regulator/Reference
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
          1. 9.2.2.2.1 Programming Output/Cathode Voltage
          2. 9.2.2.2.2 Total Accuracy
          3. 9.2.2.2.3 Stability
          4. 9.2.2.2.4 Start-Up Time
        3. 9.2.2.3 Application Curve
    3. 9.3 System Examples
    4. 9.4 Power Supply Recommendations
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
      2. 9.5.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Nomenclature
    2. 10.2 Related Links
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報
9.2.1.2.2 Output Voltage and Logic Input Level

For TL431 to properly be used as a comparator, the logic output must be readable by the receiving logic device. This is accomplished by knowing the input high and low level threshold voltage levels, typically denoted by VIH & VIL.

As seen in Figure 9-2, TL431's output low level voltage in open-loop/comparator mode is ~2 V, which is typically sufficient for 5V supplied logic. However, would not work for 3.3V& 1.8Vsupplied logic. To accommodate this a resistive divider can be tied to the output to attenuate the output voltage to a voltage legible to the receiving low voltage logic device.

TL431's output high voltage is equal to VSUP due to TL431 being open-collector. If VSUP is much higher than the receiving logic's maximum input voltage tolerance, the output must be attenuated to accommodate the outgoing logic's reliability.

When using a resistive divider on the output, be sure to make the sum of the resistive divider (R1 & R2 in Figure 9-1) is much greater than RSUP to not interfere with TL431's ability to pull close to VSUP when turning off.