JAJSMU6C June   2012  – September 2021 TPS54719

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 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 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Fixed Frequency PWM Control
      2. 7.3.2 Slope Compensation And Output Current
      3. 7.3.3 Bootstrap Voltage (Boot) And Low Dropout Operation
      4. 7.3.4 Error Amplifier
      5. 7.3.5 Voltage Reference
      6. 7.3.6 Adjusting The Output Voltage
      7. 7.3.7 Enable and Adjusting Undervoltage Lockout
      8. 7.3.8 Slow Start/Tracking Pin
      9. 7.3.9 Sequencing
    4. 7.4 Device Functional Modes
      1. 7.4.1  Constant Switching Frequency And Timing Resistor (RT Pin)
      2. 7.4.2  Overcurrent Protection
      3. 7.4.3  Frequency Shift
      4. 7.4.4  Reverse Overcurrent Protection
      5. 7.4.5  Power Good (PWRGD Pin)
      6. 7.4.6  Overvoltage Transient Protection
      7. 7.4.7  Thermal Shutdown
      8. 7.4.8  Small Signal Model For Loop Response
      9. 7.4.9  Simple Small Signal Model For Peak Current Mode Control
      10. 7.4.10 Small Signal Model For Frequency Compensation
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 High Frequency, 1.8-V Output Power Supply Design With Adjusted UVLO
      2. 8.2.2 Design Requirements
      3. 8.2.3 Detailed Design Procedure
        1. 8.2.3.1 Selecting The Switching Frequency
        2. 8.2.3.2 Output Inductor Selection
        3. 8.2.3.3 Output Capacitor
        4. 8.2.3.4 Input Capacitor
        5. 8.2.3.5 Slow-Start Capacitor
        6. 8.2.3.6 Bootstrap Capacitor Selection
        7. 8.2.3.7 Undervoltage Lockout Set Point
        8. 8.2.3.8 Output Voltage And Feedback Resistors Selection
        9. 8.2.3.9 Compensation
      4. 8.2.4 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
      1. 10.2.1 Power Dissipation Estimate
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 サポート・リソース
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

7.4.4 Reverse Overcurrent Protection

The TPS54719 implements low-side current protection by detecting the voltage across the low-side MOSFET. When the converter sinks current through its low-side FET, the control circuit turns off the low-side MOSFET if the reverse current is more than 2.7 A. By implementing this additional protection scheme, the converter is able to protect itself from excessive current during power cycling and start-up into pre-biased outputs.