ZHCSJC9G September   2006  – Jaunuary 2020 LM5069

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      典型应用图
  4. 4 修订历史记录
    1.     Device Comparison
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Current Limit
      2. 7.3.2 Circuit Breaker
      3. 7.3.3 Power Limit
      4. 7.3.4 Undervoltage Lockout (UVLO)
      5. 7.3.5 Overvoltage Lockout (OVLO)
      6. 7.3.6 Power Good Pin
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power Up Sequence
      2. 7.4.2 Gate Control
      3. 7.4.3 Fault Timer and Restart
      4. 7.4.4 Shutdown Control
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 48-V, 10-A Hot Swap Design
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Select RSNS and CL setting
          2. 8.2.1.2.2 Selecting the Hot Swap FET(s)
          3. 8.2.1.2.3 Select Power Limit
          4. 8.2.1.2.4 Set Fault Timer
          5. 8.2.1.2.5 Check MOSFET SOA
          6. 8.2.1.2.6 Set Undervoltage and Overvoltage Threshold
            1. 8.2.1.2.6.1 Option A
            2. 8.2.1.2.6.2 Option B
            3. 8.2.1.2.6.3 Option C
            4. 8.2.1.2.6.4 Option D
          7. 8.2.1.2.7 Input and Output Protection
          8. 8.2.1.2.8 Final Schematic and Component Values
        3. 8.2.1.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 PC Board Guidelines
      2. 10.1.2 System Considerations
    2. 10.2 Layout Example
  11. 11器件和文档支持
    1. 11.1 器件支持
      1. 11.1.1 开发支持
    2. 11.2 文档支持
      1. 11.2.1 相关文档
    3. 11.3 接收文档更新通知
    4. 11.4 社区资源
    5. 11.5 商标
    6. 11.6 静电放电警告
    7. 11.7 Glossary
  12. 12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

7.3.4 Undervoltage Lockout (UVLO)

The series pass MOSFET (Q1) is enabled when the input supply voltage (VSYS) is within the operating range defined by the programmable undervoltage lockout (UVLO) and overvoltage lockout (OVLO) levels. Typically the UVLO level at VSYS is set with a resistor divider (R1-R3) as shown in Figure 30. When VSYS is below the UVLO level, the internal 21-µA current source at UVLO is enabled, the current source at OVLO is off, and Q1 is held off by the
2-mA pulldown current at the GATE pin. As VSYS is increased, raising the voltage at UVLO above 2.5 V, the
21-µA current source at UVLO is switched off, increasing the voltage at UVLO, providing hysteresis for this threshold. With the UVLO pin above 2.5 V, Q1 is switched on by the 16-µA current source at the GATE pin if the insertion time delay has expired (Figure 22). See Application and Implementation for a procedure to calculate the values of the threshold setting resistors (R1-R3). The minimum possible UVLO level at VSYS can be set by connecting the UVLO pin to VIN. In this case Q1 is enabled when the VIN voltage reaches the POREN threshold.