JAJSK66A March   2021  – March 2022 TPS2521

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 Device Comparison Table
  6. 6 Pin Configuration and 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 Timing Requirements
    7. 7.7 Switching Characteristics
      1.      15
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Input Reverse Polarity Protection
      2. 8.3.2 Undervoltage Lockout (UVLO and UVP)
      3. 8.3.3 Overvoltage Clamp (OVC)
      4. 8.3.4 Inrush Current, Overcurrent, and Short Circuit Protection
        1. 8.3.4.1 Slew Rate (dVdt) and Inrush Current Control
        2. 8.3.4.2 Active Current Limiting
        3. 8.3.4.3 Short-Circuit Protection
      5. 8.3.5 Analog Load Current Monitor
      6. 8.3.6 Reverse Current Protection
      7. 8.3.7 Overtemperature Protection (OTP)
      8. 8.3.8 Fault Response
      9. 8.3.9 Power Good Indication (PG)
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Single Device, Self-Controlled
    3. 9.3 Typical Application
      1. 9.3.1 Application
      2. 9.3.2 Design Requirements
      3. 9.3.3 Detailed Design Procedure
        1. 9.3.3.1 Device Selection
        2. 9.3.3.2 Setting Undervoltage and Overvoltage Thresholds
        3. 9.3.3.3 Setting Output Voltage Rise Time (tR)
        4. 9.3.3.4 Setting Power Good Assertion Threshold
        5. 9.3.3.5 Setting Overcurrent Threshold (ILIM)
        6. 9.3.3.6 Setting Overcurrent Blanking Interval (tITIMER)
      4. 9.3.4 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Transient Protection
    2. 10.2 Output Short-Circuit Measurements
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 サポート・リソース
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

8.3.4.3 Short-Circuit Protection

During an output short-circuit event, the current through the device increases very rapidly. When a severe overcurrent condition is detected, the device triggers a fast-trip response to limit the current to a safe level. The internal fast-trip comparator employs a scalable threshold (ISC) which is equal to 2 × ILIM. This enables the user to adjust the fast-trip threshold rather than using a fixed threshold which can be too high for some low current systems. The device also employs a fixed fast-trip threshold (IFT) to protect fast protection against hard short-circuits during steady state. The fixed fast-trip threshold is higher than the maximum recommended user adjustable scalable fast-trip threshold. After the current exceeds ISC or IFT, the HFET is turned off completely within tFT. Thereafter, the devices tries to turn the HFET back ON after a short de-glitch interval (30 μs) in a current limited manner instead of a dVdt limited manner. This ensures that the HFET has a faster recovery after a transient overcurrent event and minimizes the output voltage droop. However, if the fault is persistent, the device stays in current limit causing the junction temperature to rise and eventually enter thermal shutdown. See Overtemperature Protection (OTP) section for details on the device response to overtemperature.

Figure 8-4 TPS2521xx Short-Circuit Response