JAJSDD4B July   2017  – January 2019 TPS7A92

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      代表的なアプリケーション回路
      2.      代表的なアプリケーションの図
  4. 4 改訂履歴
  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 Output Enable
      2. 7.3.2 Dropout Voltage (VDO)
      3. 7.3.3 Output Voltage Accuracy
      4. 7.3.4 High Power-Supply Ripple Rejection (PSRR)
      5. 7.3.5 Low Output Noise
      6. 7.3.6 Output Soft-Start Control
      7. 7.3.7 Power-Good Function
      8. 7.3.8 Internal Protection Circuitry
        1. 7.3.8.1 Undervoltage Lockout (UVLO)
        2. 7.3.8.2 Internal Current Limit (ICL)
        3. 7.3.8.3 Thermal Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 Normal Operation
      2. 7.4.2 Dropout Operation
      3. 7.4.3 Disabled
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Adjustable Output
      2. 8.1.2 Start-Up
        1. 8.1.2.1 Enable (EN) and Undervoltage Lockout (UVLO)
        2. 8.1.2.2 Noise-Reduction and Soft-Start Capacitor (CNR/SS)
          1. 8.1.2.2.1 Noise Reduction
          2. 8.1.2.2.2 Soft-Start and Inrush Current
      3. 8.1.3 Capacitor Recommendation
        1. 8.1.3.1 Input and Output Capacitor Requirements (CIN and COUT)
          1. 8.1.3.1.1 Load-Step Transient Response
        2. 8.1.3.2 Feed-Forward Capacitor (CFF)
      4. 8.1.4 Power Dissipation (PD)
      5. 8.1.5 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. 10.2 Layout Example
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 デバイス・サポート
      1. 11.1.1 開発サポート
        1. 11.1.1.1 評価モジュール
        2. 11.1.1.2 SPICEモデル
      2. 11.1.2 デバイスの項目表記
    2. 11.2 ドキュメントのサポート
      1. 11.2.1 関連資料
    3. 11.3 ドキュメントの更新通知を受け取る方法
    4. 11.4 コミュニティ・リソース
    5. 11.5 商標
    6. 11.6 静電気放電に関する注意事項
    7. 11.7 Glossary
  12. 12メカニカル、パッケージ、および注文情報

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

8.1.5 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 given in the Thermal Information table and are used in accordance with Equation 8.

Equation 8. TPS7A92 q_wjt-wjb_bvs204.gif

where

  • PD is the power dissipated as explained in Equation 6
  • 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

For a more detailed discussion on thermal metrics and how to use them, see the Semiconductor and IC Package Thermal Metrics application report.