JAJS381E September   2009  – September 2018 TPS54218

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      概略回路図
      2.      効率と出力電流との関係
  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 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  Fixed Frequency PWM Control
      2. 8.3.2  Slope Compensation and Output Current
      3. 8.3.3  Bootstrap Voltage (Boot) and Low Dropout Operation
      4. 8.3.4  Error Amplifier
      5. 8.3.5  Voltage Reference
      6. 8.3.6  Adjusting the Output Voltage
      7. 8.3.7  Enable and Adjusting Undervoltage Lockout
      8. 8.3.8  Soft-Start Pin
      9. 8.3.9  Sequencing
      10. 8.3.10 Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
      11. 8.3.11 Overcurrent Protection
      12. 8.3.12 Frequency Shift
      13. 8.3.13 Reverse Overcurrent Protection
      14. 8.3.14 Synchronize Using the RT/CLK Pin
      15. 8.3.15 Power Good (PWRGD Pin)
      16. 8.3.16 Overvoltage Transient Protection
      17. 8.3.17 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Small Signal Model for Loop Response
      2. 8.4.2 Simple Small Signal Model for Peak Current Mode Control
      3. 8.4.3 Small Signal Model for Frequency Compensation
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1  Step One: Select the Switching Frequency
        2. 9.2.2.2  Step Two: Select the Output Inductor
        3. 9.2.2.3  Step Three: Choose the Output Capacitor
        4. 9.2.2.4  Step Four: Select the Input Capacitor
        5. 9.2.2.5  Step Five: Minimum Load DC COMP Voltage
        6. 9.2.2.6  Step Six: Choose the Soft-Start Capacitor
        7. 9.2.2.7  Step Seven: Select the Bootstrap Capacitor
        8. 9.2.2.8  Step Eight: Undervoltage Lockout Threshold
        9. 9.2.2.9  Step Nine: Select Output Voltage and Feedback Resistors
          1. 9.2.2.9.1 Output Voltage Limitations
        10. 9.2.2.10 Step 10: Select Loop Compensation Components
        11. 9.2.2.11 Power Dissipation Estimate
      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 WEBENCH®ツールによるカスタム設計
      2. 12.1.2 開発サポート
    2. 12.2 商標
    3. 12.3 静電気放電に関する注意事項
    4. 12.4 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

8.3.11 Overcurrent Protection

The TPS54218 device implements a cycle-by-cycle current limit. During each switching cycle the high-side switch current is compared to the voltage on the COMP pin. When the instantaneous switch current intersects the COMP voltage, the high-side switch is turned off. During overcurrent conditions that pull the output voltage low, the error amplifier responds by driving the COMP pin high, increasing the switch current. The error amplifier output is clamped internally. This clamp functions as a switch current limit.