SLVSDU6D July   2017  – November 2019

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Simplified Schematic
  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
  8. Typical Characteristics
  9. Parameter Measurement Information
    1. 9.1 Temperature Coefficient
    2. 9.2 Dynamic Impedance
  10. 10Detailed Description
    1. 10.1 Overview
    2. 10.2 Functional Block Diagram
    3. 10.3 Feature Description
    4. 10.4 Device Functional Modes
      1. 10.4.1 Open Loop (Comparator)
      2. 10.4.2 Closed Loop
  11. 11Applications and Implementation
    1. 11.1 Application Information
    2. 11.2 Typical Applications
      1. 11.2.1 Comparator With Integrated Reference
        1. 11.2.1.1 Design Requirements
        2. 11.2.1.2 Detailed Design Procedure
          1. 11.2.1.2.1 Basic Operation
            1. 11.2.1.2.1.1 Overdrive
          2. 11.2.1.2.2 Output Voltage and Logic Input Level
            1. 11.2.1.2.2.1 Input Resistance
        3. 11.2.1.3 Application Curve
      2. 11.2.2 Precision Constant Current Sink
        1. 11.2.2.1 Design Requirements
        2. 11.2.2.2 Detailed Design Procedure
          1. 11.2.2.2.1 Basic Operation
            1. 11.2.2.2.1.1 Output Current Range and Accuracy
          2. 11.2.2.2.2 Power Consumption
      3. 11.2.3 Shunt Regulator/Reference
        1. 11.2.3.1 Design Requirements
        2. 11.2.3.2 Detailed Design Procedure
          1. 11.2.3.2.1 Programming Output/Cathode Voltage
          2. 11.2.3.2.2 Total Accuracy
          3. 11.2.3.2.3 Stability
          4. 11.2.3.2.4 Start-Up Time
        3. 11.2.3.3 Application Curve
      4. 11.2.4 Isolated Flyback with Optocoupler
        1. 11.2.4.1 Design Requirements
          1. 11.2.4.1.1 Detailed Design Procedure
            1. 11.2.4.1.1.1 ATL431LI Biasing
            2. 11.2.4.1.1.2 Resistor Feedback Network
    3. 11.3 System Examples
  12. 12Power Supply Recommendations
  13. 13Layout
    1. 13.1 Layout Guidelines
    2. 13.2 SOT23-3 Layout Example
    3. 13.3 X2SON (DQN) Layout Example
    4. 13.4 Thermal Considerations
  14. 14Device and Documentation Support
    1. 14.1 Documentation Support
      1. 14.1.1 Device Nomenclature
      2. 14.1.2 Related Documentation
    2. 14.2 Related Links
    3. 14.3 Receiving Notification of Documentation Updates
    4. 14.4 Community Resources
    5. 14.5 Trademarks
    6. 14.6 Electrostatic Discharge Caution
    7. 14.7 Glossary
  15. 15Mechanical, Packaging, and Orderable Information

Total Accuracy

When programming the output above unity gain (VKA=VREF), ATL431LI is susceptible to other errors that may effect the overall accuracy beyond VREF. These errors include:

  • R1 and R2 accuracies
  • VI(dev) - Change in reference voltage over temperature
  • ΔVREF / ΔVKA - Change in reference voltage to the change in cathode voltage
  • |zKA| - Dynamic impedance, causing a change in cathode voltage with cathode current

Worst case cathode voltage can be determined taking all of the variables in to account. Application note Setting the Shunt Voltage on an Adjustable Shunt Regulator, SLVA445 assists designers in setting the shunt voltage to achieve optimum accuracy for this device.