ZHCSSD8F april   2000  – july 2023 LP2980-ADJ

PRODUCTION DATA  

  1.   1
  2. 特性
  3. 应用
  4. 说明
  5. Revision History
  6. Pin Configuration and Functions
  7. 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
  8. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Output Enable
      2. 7.3.2 Dropout Voltage
      3. 7.3.3 Current Limit
      4. 7.3.4 Undervoltage Lockout (UVLO)
      5. 7.3.5 Output Pulldown
      6. 7.3.6 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Device Functional Mode Comparison
      2. 7.4.2 Normal Operation
      3. 7.4.3 Dropout Operation
      4. 7.4.4 Disabled
  9. Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 External Feedback Resistors
      2. 8.1.2 Recommended Capacitor Types
        1. 8.1.2.1 Recommended Capacitors for the New Chip
        2. 8.1.2.2 Recommended Capacitors for the Legacy Chip
      3. 8.1.3 Input and Output Capacitor Requirements
      4. 8.1.4 Feed-Forward Capacitor (CFF)
      5. 8.1.5 Reverse Current
      6. 8.1.6 Power Dissipation (PD)
      7. 8.1.7 Estimating Junction Temperature
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Setting VOUT For the LP2980-ADJ LDO
        2. 8.2.2.2 ON/OFF Input Operation
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Device Nomenclature
    2. 9.2 接收文档更新通知
    3. 9.3 支持资源
    4. 9.4 Trademarks
    5. 9.5 静电放电警告
    6. 9.6 术语表
  11. 10Mechanical, Packaging, and Orderable Information

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机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

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.