JAJSH18A March   2019  – September 2019 TPS7A78

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      ハーフブリッジ構成の標準的な回路図
      2.      フルブリッジ構成の標準的な回路図
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Active Bridge Control
      2. 8.3.2 Full-Bridge (FB) and Half-Bridge (HB) Configurations
      3. 8.3.3 4:1 Switched-Capacitor Voltage Reduction
      4. 8.3.4 Undervoltage Lockout Circuits (VUVLO_SCIN) and (VUVLO_LDO_IN)
      5. 8.3.5 Dropout Voltage Regulation
      6. 8.3.6 Current Limit
      7. 8.3.7 Programmable Power-Fail Detection
      8. 8.3.8 Power-Good (PG) Detection
      9. 8.3.9 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Normal Operation
      2. 8.4.2 Dropout Mode
      3. 8.4.3 Disabled Mode
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Recommended Capacitor Types
      2. 9.1.2 Input and Output Capacitors Requirements
      3. 9.1.3 Startup Behavior
      4. 9.1.4 Load Transient
      5. 9.1.5 Standby Power and Output Efficiency
      6. 9.1.6 Reverse Current
      7. 9.1.7 Switched-Capacitor Stage Output Impedance
      8. 9.1.8 Power Dissipation (PD)
      9. 9.1.9 Estimating Junction Temperature
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Calculating the Cap-Drop Capacitor CS
          1. 9.2.2.1.1 CS Calculations for the Typical Design
        2. 9.2.2.2 Calculating the Surge Resistor RS
          1. 9.2.2.2.1 RS Calculations for the Typical Design
        3. 9.2.2.3 Checking for the Device Maximum ISHUNT Current
          1. 9.2.2.3.1 ISHUNT Calculations for the Typical Design
        4. 9.2.2.4 Calculating the Bulk Capacitor CSCIN
          1. 9.2.2.4.1 CSCIN Calculations for the Typical Design
        5. 9.2.2.5 Calculating the PFD Pin Resistor Dividers for a Power-Fail Detection
          1. 9.2.2.5.1 PFD Pin Resistor Divider Calculations for the Typical Design
        6. 9.2.2.6 Summary of the Typical Application Design Components
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 デバイス・サポート
      1. 12.1.1 開発サポート
        1. 12.1.1.1 評価基板
        2. 12.1.1.2 SIMPLIS モデル
      2. 12.1.2 デバイスの項目表記
    2. 12.2 ドキュメントのサポート
      1. 12.2.1 関連資料
    3. 12.3 ドキュメントの更新通知を受け取る方法
    4. 12.4 コミュニティ・リソース
    5. 12.5 商標
    6. 12.6 静電気放電に関する注意事項
    7. 12.7 Glossary
  13. 13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

8.3.1 Active Bridge Control

The TPS7A78 has an internally controlled, actively clamped, full-bridge rectifier between the AC+ and AC– pins that requires one of these pins to be connected in series with the high-voltage capacitor CS and the surge resistor RS. The active clamp for the bridge is designed to stabilize the rectified DC voltage at the SCIN pin to optimize performance given the LDO output voltage. The clamp circulates any excess AC charging current from the cap-drop capacitor CS and surge resistor RS through the AC+ or the AC– pins to the GND pins when the SCIN pin voltage surpasses its UVLO_SCIN rising threshold during startup. The clamp maintains the SCIN pin voltage higher than this threshold to support the targeted output voltage. This excess AC charging current is also referred to as the shunt current, ISHUNT; see the Standby Power and Output Efficiency section for details on the shunt current.

A DC supply can also be used to provide power directly to the SCIN pin, which completely bypasses the bridge active-clamp circuit; see Table 1 for details on the DC supply mode.