ZHCSOO5I April   2004  – November 2023 TPS715A

PRODUCTION DATA  

  1.   1
  2. 特性
  3. 应用
  4. 说明
  5. Pin Configuration and Functions
  6. Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagrams
    3. 6.3 Feature Description
      1. 6.3.1 Wide Supply Range
      2. 6.3.2 Low Supply Current
      3. 6.3.3 Current Limit
      4. 6.3.4 Dropout Voltage (VDO)
    4. 6.4 Device Functional Modes
      1. 6.4.1 Normal Operation
      2. 6.4.2 Dropout Operation
  8. Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Setting VOUT for the TPS715A01 Adjustable LDO
        2. 7.2.2.2 External Capacitor Requirements
        3. 7.2.2.3 Input and Output Capacitor Requirements
        4. 7.2.2.4 Reverse Current
        5. 7.2.2.5 Feed-Forward Capacitor (CFF)
        6. 7.2.2.6 Power Dissipation (PD)
        7. 7.2.2.7 Estimating Junction Temperature
      3. 7.2.3 Application Curves
    3. 7.3 Best Design Practices
    4. 7.4 Power Supply Recommendations
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
        1. 7.5.1.1 Power Dissipation
      2. 7.5.2 Layout Example
  9. Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 Evaluation Module
        2. 8.1.1.2 Spice Models
      2. 8.1.2 Device Nomenclature
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 接收文档更新通知
    4. 8.4 支持资源
    5. 8.5 Trademarks
    6. 8.6 静电放电警告
    7. 8.7 术语表
  10. Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Estimating Junction Temperature

The JEDEC standard now recommends the use of psi (Ψ) thermal metrics to estimate the junction temperatures of the linear regulator when in-circuit on a typical PCB board application. These metrics are not thermal resistance parameters and instead offer a practical and relative way to estimate junction temperature. These psi metrics are determined to be significantly independent of the copper area available for heat-spreading. The Thermal Information table lists the primary thermal metrics, which are the junction-to-top characterization parameter (ψJT) and junction-to-board characterization parameter (ψJB). These parameters provide two methods for calculating the junction temperature (TJ), as described in the following equations. Use the junction-to-top characterization parameter (ψJT) with the temperature at the center-top of device package (TT) to calculate the junction temperature. Use the junction-to-board characterization parameter (ψJB) with the PCB surface temperature 1 mm from the device package (TB) to calculate the junction temperature.

Equation 9. TJ = TT + ψJT × PD

where:

  • PD is the dissipated power
  • TT is the temperature at the center-top of the device package
Equation 10. TJ = TB + ψJB × PD

where:

  • TB is the PCB surface temperature measured 1 mm from the device package and centered on the package edge

For detailed information on the thermal metrics and how to use them, see the Semiconductor and IC Package Thermal Metrics application note.