SBVS296B September   2017  – June 2018 TPS7A52-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Powering RF Components
      2.      Output Voltage Noise vs Frequency and Output Voltage
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 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 Voltage Regulation Features
        1. 7.3.1.1 DC Regulation
        2. 7.3.1.2 AC and Transient Response
      2. 7.3.2 System Start-Up Features
        1. 7.3.2.1 Programmable Soft Start (NR/SS Pin)
        2. 7.3.2.2 Internal Sequencing
          1. 7.3.2.2.1 Enable (EN)
          2. 7.3.2.2.2 Undervoltage Lockout (UVLO) Control
          3. 7.3.2.2.3 Active Discharge
        3. 7.3.2.3 Power-Good Output (PG)
      3. 7.3.3 Internal Protection Features
        1. 7.3.3.1 Foldback Current Limit (ICL)
        2. 7.3.3.2 Thermal Protection (Tsd)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Regulation
      2. 7.4.2 Disabled
      3. 7.4.3 Current Limit Operation
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1  Recommended Capacitor Types
        1. 8.1.1.1 Input and Output Capacitor Requirements (CIN and COUT)
        2. 8.1.1.2 Noise-Reduction and Soft-Start Capacitor (CNR/SS)
        3. 8.1.1.3 Feed-Forward Capacitor (CFF)
      2. 8.1.2  Soft-Start and Inrush Current
      3. 8.1.3  Optimizing Noise and PSRR
      4. 8.1.4  Charge Pump Noise
      5. 8.1.5  Current Sharing
      6. 8.1.6  Adjustable Operation
      7. 8.1.7  Power-Good Operation
      8. 8.1.8  Undervoltage Lockout (UVLO) Operation
      9. 8.1.9  Dropout Voltage (VDO)
      10. 8.1.10 Load Transient Response
      11. 8.1.11 Reverse Current Protection Considerations
      12. 8.1.12 Power Dissipation (PD)
      13. 8.1.13 Estimating Junction Temperature
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Board Layout
      2. 10.1.2 RTK Package—High CTE Mold Compound
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Evaluation Modules
        2. 11.1.1.2 Reference Designs
        3. 11.1.1.3 Spice Models
      2. 11.1.2 Device Nomenclature
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

7.3.3.2 Thermal Protection (Tsd)

The thermal shutdown circuit protects the LDO against excessive heat in the system, either resulting from current limit or high ambient temperature.

The output of the LDO turns off when the LDO temperature (junction temperature, TJ) exceeds the rising thermal shutdown temperature. The output turns on again after TJ decreases below the falling thermal shutdown temperature.

A high power dissipation across the device, combined with a high ambient temperature (TA), can cause TJ to be greater than or equal to Tsd, triggering the thermal shutdown and causing the output to fall to 0 V. The LDO can cycle on and off when thermal shutdown is reached under these conditions.