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

8.1.13 Estimating Junction Temperature

The JEDEC standard now recommends the use of psi (Ψ) thermal metrics to estimate the junction temperatures of the LDO when in-circuit on a typical PCB board application. These metrics are not strictly speaking thermal resistances, but rather offer practical and relative means of estimating junction temperatures. These psi metrics are determined to be significantly independent of the copper-spreading area. The key thermal metrics (ΨJT and ΨJB) are used in accordance with Equation 8 and are given in the Electrical Characteristics table.

Equation 8. TPS7A52-Q1 q_wjt-wjb_bvs204.gif

where

  • PD is the power dissipated as explained in Equation 5
  • TT is the temperature at the center-top of the device package, and
  • TB is the PCB surface temperature measured 1 mm from the device package and centered on the package edge