SNVSBA4A May   2019  – November 2019 TL431LI-Q1 , TL432LI-Q1

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 Recommended Operating Conditions
    4. 7.4 Thermal Information
    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
      2. 10.2.2 Design Requirements
      3. 10.2.3 Detailed Design Procedure
        1. 10.2.3.1 Basic Operation
          1. 10.2.3.1.1 Overdrive
        2. 10.2.3.2 Output Voltage and Logic Input Level
          1. 10.2.3.2.1 Input Resistance
      4. 10.2.4 Application Curves
      5. 10.2.5 Precision LED Lighting Current Sink Regulator
        1. 10.2.5.1 Design Requirements
        2. 10.2.5.2 Detailed Design Procedure
          1. 10.2.5.2.1 Basic Operation
            1. 10.2.5.2.1.1 Output Current Range and Accuracy
          2. 10.2.5.2.2 Power Consumption
      6. 10.2.6 Shunt Regulator/Reference
        1. 10.2.6.1 Design Requirements
        2. 10.2.6.2 Detailed Design Procedure
          1. 10.2.6.2.1 Programming Output/Cathode Voltage
          2. 10.2.6.2.2 Total Accuracy
          3. 10.2.6.2.3 Stability
          4. 10.2.6.2.4 Start-up Time
        3. 10.2.6.3 Application Curves
      7. 10.2.7 Isolated Flyback with Optocoupler
        1. 10.2.7.1 Design Requirements
        2. 10.2.7.2 Detailed Design Procedure
          1. 10.2.7.2.1 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 Device Support
      1. 13.1.1 Device Nomenclature
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Related Links
    4. 13.4 Receiving Notification of Documentation Updates
    5. 13.5 Support Resources
    6. 13.6 Trademarks
    7. 13.7 Electrostatic Discharge Caution
    8. 13.8 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

3 Description

The TL431LI-Q1 is a three-terminal adjustable shunt regulator, with specified thermal stability over applicable automotive, commercial, and military temperature ranges. The output voltage can be set to any value between Vref (approximately 2.495 V) and 36 V with two external resistors. The device has a typical output impedance of 0.3 Ω. Its active output circuitry provides a very sharp turn-on characteristic, making it an excellent replacement for Zener diodes in many applications, such as onboard regulation, adjustable power supplies, and switching power supplies. This device is a pin-to-pin alternative to the industry standard TL431-Q1 with optimized Iref and IIdev performance. The lower Iref and IIdev values of the TL431LI-Q1 enable designers to achieve higher system accuracy and lower leakage current. The TL432LI-Q1 has exactly the same functionality and electrical specifications as the TL431LI-Q1, but has a different pinout for the DBZ package.

The TL431LI-Q1 is offered in two grades, with initial tolerances (at 25°C) of 0.5% and 1%, for the B and A grade, respectively. The TL431LI-Q1 is also available in two temperature grades: grade 1 (denoted by a 'Q' in the part number), and grade 0 (denoted by a 'E' in the part number), which represent maximum ambient operating temperatures of 125°C and 150°C respectively. The TL43xLI-Q1 is characterized for operation from –40°C to 125°C for grade 1, and –40°C to 150°C for grade 0, and its low output drift versus temperature ensures good stability over the entire temperature range.

Device Information(1)

PART NUMBER PACKAGE (PIN) BODY SIZE (NOM)
TL43xLI-Q1 SOT-23 (3) 2.90 mm x 1.30 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.