SLVSDQ6A July   2018  – November 2018 TL431LI , TL432LI

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 Thermal Information
    4. 7.4 Recommended Operating Conditions
    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
        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 Precision Constant Current Sink
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
          1. 10.2.2.2.1 Basic Operation
            1. 10.2.2.2.1.1 Output Current Range and Accuracy
          2. 10.2.2.2.2 Power Consumption
      3. 10.2.3 Shunt Regulator/Reference
        1. 10.2.3.1 Design Requirements
        2. 10.2.3.2 Detailed Design Procedure
          1. 10.2.3.2.1 Programming Output/Cathode Voltage
          2. 10.2.3.2.2 Total Accuracy
          3. 10.2.3.2.3 Stability
          4. 10.2.3.2.4 Start-up Time
        3. 10.2.3.3 Application Curve
      4. 10.2.4 Isolated Flyback with Optocoupler
        1. 10.2.4.1 Design Requirements
          1. 10.2.4.1.1 Detailed Design Procedure
            1. 10.2.4.1.1.1 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 Related Links
    2. 13.2 Documentation Support
      1. 13.2.1 Device Nomenclature
      2. 13.2.2 Related Documentation
    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

10.2.3.2.1 Programming Output/Cathode Voltage

In order to program the cathode voltage to a regulated voltage a resistive bridge must be shunted between the cathode and anode pins with the mid point tied to the reference pin. This can be seen in Figure 23, with R1 and R2 being the resistive bridge. The cathode/output voltage in the shunt regulator configuration can be approximated by the equation shown in Figure 23. The cathode voltage can be more accurate determined by taking in to account the cathode current:

Equation 1. Vo=(1+R1/R2)VREF-IREFR1

In order for this equation to be valid, TL43xLI must be fully biased so that it has enough open loop gain to mitigate any gain error. This can be done by meeting the Imin spec denoted in Specifications.