JAJSIC3D October   1997  – December 2019 OPA548

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
    1.     概略回路図
  3. 3 概要
  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 Adjustable Current Limit
      2. 7.3.2 Enable/Status (E/S) Pin
      3. 7.3.3 Thermal Shutdown Status
    4. 7.4 Device Functional Modes
      1. 7.4.1 Output Disable
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Basic Circuit Connections
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Power Supply Requirements
          2. 8.2.1.2.2 Gain Setting and Input Configuration
          3. 8.2.1.2.3 Current Limit
          4. 8.2.1.2.4 Safe-Operating-Area
          5. 8.2.1.2.5 Heat Sinking
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Monitoring Single- and Dual-Supplies
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Output Disable and Thermal Shutdown Status
      3. 8.2.3 Programmable Power Supply
    3. 8.3 System Examples
  9. 9 Power Supply Recommendations
    1. 9.1 Output Stage Compensation
    2. 9.2 Output Protection
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Safe Operating Area
      2. 10.1.2 Amplifier Mounting
      3. 10.1.3 Power Dissipation
      4. 10.1.4 Thermal Considerations
      5. 10.1.5 Heat Sinking
        1. 10.1.5.1 Heat Sink Selection Example
    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 デベロッパー・ネットワークの製品に関する免責事項
    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 サポート・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

10.1.5 Heat Sinking

Most applications require a heat sink to assure that the maximum operating junction temperature (125°C) is not exceeded. In addition, the junction temperature should be kept as low as possible for increased reliability. Junction temperature can be determined according to the equation:

Equation 2. TJ = TA + PDRθJA

where

  • RθJA = RθJC + RθCH + RθHA
  • TJ = Junction Temperature (°C)
  • TA = Ambient Temperature (°C)
  • PD = Power Dissipated (W)
  • RθJC = Junction-to-Case Thermal Resistance (°C/W)
  • RθCH = Case-to-Heat Sink Thermal Resistance (°C/W)
  • RθHA = Heat Sink-to-Ambient Thermal Resistance (°C/W)
  • RθJA = Junction-to-Air Thermal Resistance (°C/W)

Figure 44 shows maximum power dissipation versus ambient temperature with and without the use of a heat sink. Using a heat sink significantly increases the maximum power dissipation at a given ambient temperature as shown.

The difficulty in selecting the heat sink required lies in determining the power dissipated by the OPA548. For DC output into a purely resistive load, power dissipation is simply the load current times the voltage developed across the conducting output transistor, PD = IL(VS–VO). Other loads are not as simple. Consult Application Bulletin SBOA022 for further insight on calculating power dissipation. Once power dissipation for an application is known, the proper heat sink can be selected.

OPA548 maxpowerdis1.gifFigure 44. Maximum Power Dissipation vs Ambient Temperature