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

9.2.1.2.9 External UVLO

In some cases, an input UVLO level different than that provided internal to the device is needed. This can be accomplished by using the circuit shown in Figure 14. The input voltage at which the device turns on is designated VON and the turnoff voltage is VOFF. First, a value for RENB is chosen in the range of 10 kΩ to 100 kΩ and then Equation 10 is used to calculate RENT and VOFF.

LMR36520 EN_uvlo_sch1.gifFigure 14. Setup for External UVLO Application
Equation 10. LMR36520 EN_uvlo_eq1.gif

where

  • VON = VIN turnon voltage
  • VOFF = VIN turnoff voltage