ZHCSKA2A September   2019  – February 2020 LMR36520

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      效率与输出电流间的关系 VOUT = 5V，400kHz
      2.      简化原理图
  4. 4 修订历史记录
  5. 5 Device Comparison Table
  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 Timing Requirements
    7. 7.7 Switching Characteristics
    8. 7.8 System Characteristics
    9. 7.9 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 Power-Good Flag Output
      2. 8.3.2 Enable and Start-up
      3. 8.3.3 Current Limit and Short Circuit
      4. 8.3.4 Undervoltage Lockout and Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Auto Mode
      2. 8.4.2 Forced PWM Operation
      3. 8.4.3 Dropout
      4. 8.4.4 Minimum Switch On-Time
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design 1: Low Power 24-V, 2-A Buck Converter
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1  Choosing the Switching Frequency
          2. 9.2.1.2.2  Setting the Output Voltage
          3. 9.2.1.2.3  Inductor Selection
          4. 9.2.1.2.4  Output Capacitor Selection
          5. 9.2.1.2.5  Input Capacitor Selection
          6. 9.2.1.2.6  CBOOT
          7. 9.2.1.2.7  VCC
          8. 9.2.1.2.8  CFF Selection
          9. 9.2.1.2.9  External UVLO
          10. 9.2.1.2.10 Maximum Ambient Temperature
      2. 9.2.2 Application Curves
    3. 9.3 What to Do and What Not to Do
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Ground and Thermal Considerations
    2. 11.2 Layout Example
  12. 12器件和文档支持
    1. 12.1 器件支持
      1. 12.1.1 开发支持
    2. 12.2 文档支持
      1. 12.2.1 相关文档
    3. 12.3 接收文档更新通知
    4. 12.4 支持资源
    5. 12.5 商标
    6. 12.6 静电放电警告
    7. 12.7 Glossary
  13. 13机械、封装和可订购信息

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

8.3.4 Undervoltage Lockout and Thermal Shutdown

The LMR36520 incorporates an undervoltage lockout feature on the output of the internal LDO at the VCC pin. When VCC reaches about 3.7 V, the device is ready to receive an EN signal and start up. When VCC falls below about 3 V, the device shuts down, regardless of EN status. Because the LDO is in dropout during these transitions, the previously mentioned values roughly represent the input voltage levels during the transitions.

Thermal shutdown is provided to protect the regulator from excessive junction temperature. When the junction temperature reaches about 170°C, the device shuts down; re-start occurs when the temperature falls to about 158°C. For safe operation, the device must not be allowed to go into a short circuit condition while in thermal shutdown.