ZHCSLO5 December   2020 LM25149

ADVANCE INFORMATION  

  1. 特性
  2. 应用
  3. 说明
  4. Revision History
  5. Description (continued)
  6. Pin Configuration and Functions
    1. 6.1 Wettable Flanks
  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 Active EMI Filter
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Input Voltage Range (VIN)
      2. 8.3.2  High-Voltage Bias Supply Regulator (VCC, VCCX, VDDA)
      3. 8.3.3  Enable (EN)
      4. 8.3.4  Power Good Monitor (PG)
      5. 8.3.5  Switching Frequency (RT)
      6. 8.3.6  Active EMI Filter
      7. 8.3.7  Dual Random Spread Spectrum (DRSS)
      8. 8.3.8  Soft-Start
      9. 8.3.9  Output Voltage Setpoint (FB)
      10. 8.3.10 Minimum Controllable On-Time
      11. 8.3.11 Error Amplifier and PWM Comparator (FB, EXTCOMP)
      12. 8.3.12 Slope Compensation
      13. 8.3.13 Inductor Current Sense (ISNS+, VOUT)
        1. 8.3.13.1 Shunt Current Sensing
        2. 8.3.13.2 Inductor DCR Current Sensing
      14. 8.3.14 Hiccup Mode Current Limiting
      15. 8.3.15 High-Side and Low-Side Gate Drivers (HO, LO)
      16. 8.3.16 Output Configurations (CNFG)
      17. 8.3.17 Single-Output Two-phase Operation
    4. 8.4 Device Functional Modes
      1. 8.4.1 Standby Modes
      2. 8.4.2 Pulse Frequency Modulation and Synchronization (PFM/SYNC)
      3. 8.4.3 Thermal Shutdown
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Power Train Components
        1. 9.1.1.1 Buck Inductor
        2. 9.1.1.2 Output Capacitors
        3. 9.1.1.3 Input Capacitors
        4. 9.1.1.4 Power MOSFETs
        5. 9.1.1.5 EMI Filter
      2. 9.1.2 Error Amplifier and Compensation
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Custom Design With WEBENCH® Tools
        2. 9.2.2.2 Custom Design With Excel Quickstart Tool
        3. 9.2.2.3 Buck Inductor
        4. 9.2.2.4 Current-Sense Resistance
        5. 9.2.2.5 Output Capacitors
        6. 9.2.2.6 Input Capacitors
        7. 9.2.2.7 Frequency Set Resistor
        8. 9.2.2.8 Feedback Resistors
        9. 9.2.2.9 Compensation Components
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Power Stage Layout
      2. 11.1.2 Gate-Drive Layout
      3. 11.1.3 PWM Controller Layout
      4. 11.1.4 Active EMI Layout
      5. 11.1.5 Thermal Design and Layout
      6. 11.1.6 Ground Plane Design
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
      2. 12.1.2 Custom Design With WEBENCH® Tools
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
        1. 12.2.1.1 PCB Layout Resources
        2. 12.2.1.2 Thermal Design Resources
    3. 12.3 接收文档更新通知
    4. 12.4 支持资源
    5. 12.5 Trademarks
    6. 12.6 静电放电警告
    7. 12.7 术语表
  13. 13Mechanical, 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

特性

  • 两个集成式 EMI 缓解机制
    • 有源 EMI 滤波器,可提高低频下的 EMI 性能
    • 双随机扩频 (DRSS),可提高低频和高频频带上的 EMI 性能
    • EMI 平均降低了 25dBµV
    • 减小了 50% 的外部差分模式滤波器大小并降低了系统成本
  • 多功能同步降压直流/直流控制器
    • 3.5V 至 42V 的宽输入电压范围
    • 1% 精度、3.3V/5V/12V 固定电压或 0.8V 至 36V 可调输出电压
    • 150°C 最大结温
    • 关断模式电流:2.2µA
    • 空载待机电流:9µA
  • 开关频率范围为 100kHz 至 2.2MHz
    • 同步输入和同步输出功能
  • 固有保护特性,可实现稳健的设计
    • 内部断续模式过流保护
    • 使能和 PGOOD 功能
    • VCC、VDDA 和栅极驱动 UVLO 保护
    • 内部或外部环路补偿
    • 具有迟滞功能的热关断保护
  • 使用 LM25149 并借助 WEBENCH® Power Designer 创建定制设计方案