ZHCSNC8A February   2021  – March 2021 TPS541620

PRODUCTION DATA  

  1. 1 特性
  2. 2 应用
  3. 3 说明
  4. 4 Revision History
  5. 5 Pin Configuration and 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  Fixed-Frequency, Internally Compensated Advanced-Current-Mode Control
      2. 7.3.2  Enable and UVLO
      3. 7.3.3  Internal LDO
      4. 7.3.4  Pre-biased Output Start-up
      5. 7.3.5  Current Sharing
      6. 7.3.6  Frequency Selection and Minimum On-Time and Off-Time
      7. 7.3.7  Ramp Compensation Selection
      8. 7.3.8  Soft Start
      9. 7.3.9  Remote Sense Function
      10. 7.3.10 Adjustable Output Voltage
      11. 7.3.11 Power Good
      12. 7.3.12 Overcurrent Protection
      13. 7.3.13 Overvoltage and Undervoltage Protection
      14. 7.3.14 Overtemperature Protection
      15. 7.3.15 Frequency Synchronization
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application - Dual Independent Outputs
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1  Switching Frequency
        2. 8.2.2.2  Output Inductor Selection
        3. 8.2.2.3  Output Capacitor
        4. 8.2.2.4  Input Capacitor
        5. 8.2.2.5  Output Voltage Resistors Selection
        6. 8.2.2.6  Adjustable Undervoltage Lockout
        7. 8.2.2.7  Bootstrap Capacitor Selection
        8. 8.2.2.8  BP5 Capacitor Selection
        9. 8.2.2.9  PGOOD Pullup Resistor
        10. 8.2.2.10 Current Limit
        11. 8.2.2.11 Soft-Start Time Selection
        12. 8.2.2.12 MODE1 and MODE2 Pins
      3. 8.2.3 Application Curves
      4. 8.2.4 Typical Application - 2-Phase Operation
        1. 8.2.4.1 Design Requirements
        2. 8.2.4.2 Detailed Design Procedure
          1. 8.2.4.2.1  Switching Frequency
          2. 8.2.4.2.2  Output Inductor Selection
          3. 8.2.4.2.3  Output Capacitor
          4. 8.2.4.2.4  Input Capacitor
          5. 8.2.4.2.5  Output Voltage Resistors Selection
          6. 8.2.4.2.6  Adjustable Undervoltage Lockout
          7. 8.2.4.2.7  Bootstrap Capacitor Selection
          8. 8.2.4.2.8  BP5 Capacitor Selection
          9. 8.2.4.2.9  PGOOD Pullup Resistor
          10. 8.2.4.2.10 Current Limit
          11. 8.2.4.2.11 Soft-Start Time Selection
          12. 8.2.4.2.12 MODE1 Pin
        3. 8.2.4.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
      1. 10.2.1 Thermal Performance
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 第三方产品免责声明
    2. 11.2 接收文档更新通知
    3. 11.3 支持资源
    4. 11.4 Trademarks
    5. 11.5 静电放电警告
    6. 11.6 术语表
  12. 12Mechanical, 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

10.1 Layout Guidelines

Layout is a critical portion of good power supply design. See Figure 10-1 for a PCB layout example. Key guidelines to follow for the layout are:

  • VIN, PGND, and SW traces must be as wide as possible to reduce trace impedance and improve heat dissipation.
  • Place a 10-nF to 100-nF capacitor from each VIN to PGND pin and place them as close as possible to the device (It is recommended the edge of input bypass capacitor pads to be no more than 8 mils away from the VIN pin). Place the remaining ceramic input capacitance next to these high frequency bypass capacitors.
  • Use multiple vias near the PGND pins and use the layer directly below the device to connect them together. This helps to minimize noise and can help heat dissipation.
  • Use vias near both VIN pins and provide a low impedance connection between them through an internal layer.
  • Place the inductor as close as possible to the device to minimize the length of the SW node routing.
  • Place the BOOT-SW capacitor as close as possible to the BOOT and SW pins. If a boot resistor is needed, the value of the resistor should be no more than 10 Ω.
  • Place the BP5 capacitor as close as possible to the BP5 and PGND pins.
  • Place the bottom resistor in the FB divider as close as possible to the FB and AGND pins of the IC. Also keep the upper feedback resistor and the feedforward capacitor, if used, near the IC. Connect the FB divider to the output voltage at the desired point of regulation.
  • Return the MODE1 and MODE2 resistors to a quiet AGND island.
  • Use multiple vias in the AGND island to connect it back to internal PGND layers. Place the vias near the BP5 cap but away from the bottom FB resistor.