SNVSBA4A May   2019  – November 2019 TL431LI-Q1 , TL432LI-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Temperature Coefficient
    2. 8.2 Dynamic Impedance
  9. 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
      2. 10.2.2 Design Requirements
      3. 10.2.3 Detailed Design Procedure
        1. 10.2.3.1 Basic Operation
          1. 10.2.3.1.1 Overdrive
        2. 10.2.3.2 Output Voltage and Logic Input Level
          1. 10.2.3.2.1 Input Resistance
      4. 10.2.4 Application Curves
      5. 10.2.5 Precision LED Lighting Current Sink Regulator
        1. 10.2.5.1 Design Requirements
        2. 10.2.5.2 Detailed Design Procedure
          1. 10.2.5.2.1 Basic Operation
            1. 10.2.5.2.1.1 Output Current Range and Accuracy
          2. 10.2.5.2.2 Power Consumption
      6. 10.2.6 Shunt Regulator/Reference
        1. 10.2.6.1 Design Requirements
        2. 10.2.6.2 Detailed Design Procedure
          1. 10.2.6.2.1 Programming Output/Cathode Voltage
          2. 10.2.6.2.2 Total Accuracy
          3. 10.2.6.2.3 Stability
          4. 10.2.6.2.4 Start-up Time
        3. 10.2.6.3 Application Curves
      7. 10.2.7 Isolated Flyback with Optocoupler
        1. 10.2.7.1 Design Requirements
        2. 10.2.7.2 Detailed Design Procedure
          1. 10.2.7.2.1 TL431 Feedback Loop Error Calculation
    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 Support
      1. 13.1.1 Device Nomenclature
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Related Links
    4. 13.4 Receiving Notification of Documentation Updates
    5. 13.5 Support Resources
    6. 13.6 Trademarks
    7. 13.7 Electrostatic Discharge Caution
    8. 13.8 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.4.1 Open Loop (Comparator)

When the cathode/output voltage or current of TL43xLI-Q1 is not being fed back to the reference/input pin in any form, this device is operating in open loop. With proper cathode current (Ika) applied to this device, TL43xLI-Q1 has the characteristics shown in Figure 18. With such high gain in this configuration, TL43xLI-Q1 is typically used as a comparator. Since the reference is integrated, TL43xLI-Q1 is the preferred choice when users are trying to monitor a certain level of a single signal. Refer to the Using the TL431 as a Voltage Comparator Application Report for more details on open loop comparator applications on the TL431LI-Q1.