ZHCSOW9C october   2022  – july 2023 TPSM82912 , TPSM82913 , TPSM82913E

PRODUCTION DATA  

  1.   1
  2. 1 特性
  3. 2 应用
  4. 3 说明
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Smart Config (S-CONF)
      2. 7.3.2  Device Enable (EN/SYNC)
      3. 7.3.3  Device Synchronization (EN/SYNC)
      4. 7.3.4  Spread Spectrum Modulation
      5. 7.3.5  Output Discharge
      6. 7.3.6  Undervoltage Lockout (UVLO)
      7. 7.3.7  Power-Good Output
      8. 7.3.8  Noise Reduction and Soft-Start Capacitor (NR/SS)
      9. 7.3.9  Current Limit and Short-Circuit Protection
      10. 7.3.10 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Fixed Frequency Pulse Width Modulation
      2. 7.4.2 Low Duty Cycle Operation
      3. 7.4.3 High Duty Cycle Operation (100% Duty Cycle)
      4. 7.4.4 Second Stage L-C Filter Compensation (Optional)
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 External Component Selection
          1. 8.2.2.2.1 Switching Frequency Selection
          2. 8.2.2.2.2 Output Capacitor Selection
          3. 8.2.2.2.3 Ferrite Bead Selection for Second L-C Filter
          4. 8.2.2.2.4 Input Capacitor Selection
          5. 8.2.2.2.5 Setting the Output Voltage
          6. 8.2.2.2.6 NR/SS Capacitor Selection
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 第三方产品免责声明
      2. 9.1.2 Development Support
        1. 9.1.2.1 Custom Design With WEBENCH® Tools
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 接收文档更新通知
    4. 9.4 支持资源
    5. 9.5 Trademarks
    6. 9.6 静电放电警告
    7. 9.7 术语表
  11. 10Mechanical, Packaging, and Orderable Information

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

7.4.3 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. GUID-73464B00-4E91-41CC-BB32-A0B686A95ADC-low.gif

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,

    76 mΩ for the TPSM8291x

To maintain fixed frequency switching, the device requires a minimum off-time of 50 ns (typical), 60 ns (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.