JAJSIY4 April   2020 TPS7B81

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 説明
    1.     Device Images
      1.      代表的なアプリケーションの回路図
      2.      静止電流と周囲温度の関係 (VOUT = 3.3V)
  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 Device Enable (EN)
      2. 7.3.2 Undervoltage Shutdown
      3. 7.3.3 Current Limit
      4. 7.3.4 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation With VIN Lower Than 3 V
      2. 7.4.2 Operation With VIN Larger Than 3 V
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Power Dissipation
        1. 8.1.1.1 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 Input Capacitor
        2. 8.2.2.2 Output Capacitor
      3. 8.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    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 ドキュメントの更新通知を受け取る方法
    2. 11.2 サポート・リソース
    3. 11.3 商標
    4. 11.4 静電気放電に関する注意事項
    5. 11.5 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

8.1.1.1 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 resistance, 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 4 and given in the Thermal Information table.

Equation 4. TPS7B81 q_wjt-wjb_bvs204.gif

where

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