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

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% or 1.0%) depending on which version is being used. The more overdrive voltage provided, the faster the ATL431LI will respond.

For applications where ATL431LI is being used as a comparator, it is best to set the trip point to greater than the positive expected error (that is +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, TI recommends to use an input resistor <10kΩ to provide Iref.