SLVS905B December   2008  – July 2024 TLV431A-Q1 , TLV431B-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
    1.     Pin Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Thermal Information
    4. 5.4 Recommended Operating Conditions
    5. 5.5 Electrical Characteristics for TLV431A-Q1
    6. 5.6 Electrical Characteristics for TLV431B-Q1
    7. 5.7 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
    4. 7.4 Device Functional Modes
      1. 7.4.1 Open Loop (Comparator)
      2. 7.4.2 Closed Loop
  9. 8 Applications and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Comparator with Integrated Reference (Open Loop)
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Basic Operation
          2. 8.2.1.2.2 Overdrive
          3. 8.2.1.2.3 Output Voltage and Logic Input Level
            1. 8.2.1.2.3.1 Input Resistance
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Shunt Regulator/Reference
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Programming Output/Cathode Voltage
          2. 8.2.2.2.2 Total Accuracy
          3. 8.2.2.2.3 Stability
        3. 8.2.2.3 Application Curve
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
8.2.2.2.1 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 8-5, 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 8-5. The cathode voltage can be more accurately determined by taking in to account the cathode current:

VO=(1+R1/R2)*Vref–Iref*R1

For this equation to be valid, TLV431 must be fully biased so that there is enough open loop gain to mitigate any gain error. This can be done by meeting the Imin spec denoted in Section 5.4 table.