JAJSPL2 October   2024 TPSM82916

ADVANCE INFORMATION  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Smart Config (S-CONF)
      2. 6.3.2  Device Enable (EN/SYNC)
      3. 6.3.3  Device Synchronization (EN/SYNC)
      4. 6.3.4  Spread Spectrum Modulation
      5. 6.3.5  Output Discharge
      6. 6.3.6  Undervoltage Lockout (UVLO)
      7. 6.3.7  Power-Good Output
      8. 6.3.8  Noise Reduction and Soft-Start Capacitor (NR/SS)
      9. 6.3.9  Current Limit and Short-Circuit Protection
      10. 6.3.10 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Fixed Frequency Pulse Width Modulation
      2. 6.4.2 Low Duty Cycle Operation
      3. 6.4.3 High Duty Cycle Operation (100% Duty Cycle)
      4. 6.4.4 Second Stage L-C Filter Compensation (Optional)
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Custom Design With WEBENCH® Tools
        2. 7.2.2.2 External Component Selection
          1. 7.2.2.2.1 Switching Frequency Selection
          2. 7.2.2.2.2 Output Capacitor Selection
          3. 7.2.2.2.3 Ferrite Bead Selection for Second L-C Filter
          4. 7.2.2.2.4 Input Capacitor Selection
          5. 7.2.2.2.5 Setting the Output Voltage
          6. 7.2.2.2.6 NR/SS Capacitor Selection
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 サード・パーティ製品に関する免責事項
      2. 8.1.2 Development Support
        1. 8.1.2.1 Custom Design With WEBENCH® Tools
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 ドキュメントの更新通知を受け取る方法
    4. 8.4 サポート・リソース
    5. 8.5 Trademarks
    6. 8.6 静電気放電に関する注意事項
    7. 8.7 用語集
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

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）
  • VCE|16
サーマルパッド・メカニカル・データ
発注情報

6.4.3 High Duty Cycle Operation (100% Duty Cycle)

The device offers a low input-to-output voltage differential by entering 100% duty cycle mode. In this mode, the high-side MOSFET switch is constantly turned on. The minimum input voltage to maintain output voltage regulation, depending on the load current and the output voltage level, is calculated as:

Equation 2. V I N   ( m i n ) = V O U T ( m i n ) + I O U T × R D S ( O N )   +   R L

where

  • VOUT(min) is the minimum output voltage the load can accept.
  • IOUT is the output current.
  • RDS(ON) is the RDS(ON) of the high-side MOSFET.
  • RL is the DC resistance of the inductor used.

To maintain fixed frequency switching, the device requires a minimum off-time of 50ns (typical), 60ns (maximum). If this limit is reached during a switching pulse, the device skips switching pulses to maintain output voltage regulation. If the input voltage decreases further, the device enters 100% mode.