SNVSCR4 July   2024 TLA431

ADVANCE INFORMATION  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  8. Parameter Measurement Information
    1. 7.1 Temperature Coefficient
    2. 7.2 Dynamic Impedance
  9. 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 Closed Loop
      2. 8.4.2 Open Loop (Comparator)
  10. Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Shunt Regulator/Reference
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Programming Output/Cathode Voltage
          2. 9.2.1.2.2 Total Accuracy
          3. 9.2.1.2.3 Stability
          4. 9.2.1.2.4 Start-Up Time
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Comparator With Integrated Reference
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
          1. 9.2.2.2.1 Basic Operation
            1. 9.2.2.2.1.1 Overdrive
          2. 9.2.2.2.2 Output Voltage and Logic Input Level
            1. 9.2.2.2.2.1 Input Resistance
        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

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Programming Output/Cathode Voltage

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 9-1, with R1 & R2 being the resistive bridge. The cathode/output voltage in the shunt regulator configuration can be approximated by the equation shown in Figure 9-1. The cathode voltage can be more accuratel determined by taking in to account the cathode current:

Vo=(1+R1/R2)*VREF-IREF*R1

For this equation to be valid, TLA431 must be fully biased so that the TLA431 has enough open loop gain to mitigate any gain error. This can be done by meeting the Imin spec denoted in Electrical Characteristics.