ZHCS518E April   1998  – June 2019 LM2588

PRODUCTION DATA.  

  1. 1 特性
  2. 2 典型 应用
  3. 3 说明
    1.     Device Images
      1.      反激式稳压器
  4. 4 修订历史记录
  5. 5 Pin Configurations
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Ratings
    4. 6.4 Electrical Characteristics: 3.3 V
    5. 6.5 Electrical Characteristics: 5 V
    6. 6.6 Electrical Characteristics: 12 V
    7. 6.7 Electrical Characteristics: Adjustable
    8. 6.8 Electrical Characteristics: All Output Voltage Versions
    9. 6.9 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 Flyback Regulator Operation
      2. 7.3.2 Step-Up (Boost) Regulator Operation
      3. 7.3.3 Shutdown Control
      4. 7.3.4 Frequency Adjustment
      5. 7.3.5 Frequency Synchronization
      6. 7.3.6 Programming Output Voltage (Selecting R1 And R2)
      7. 7.3.7 Short-Circuit Condition
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Typical Flyback Regulator Applications
        1. 8.2.1.1 Design Requirements
          1. 8.2.1.1.1 Transformer Selection (T)
          2. 8.2.1.1.2 Transformer Footprints
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2 Flyback Regulator Input Capacitors
          3. 8.2.1.2.3 Switch Voltage Limits
          4. 8.2.1.2.4 Output Voltage Limitations
          5. 8.2.1.2.5 Noisy Input Line Condition
          6. 8.2.1.2.6 Stability
      2. 8.2.2 Typical Boost Regulator Applications
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
    3. 8.3 System Examples
      1. 8.3.1 Test Circuits
  9. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
    3. 9.3 Heat Sink/Thermal Considerations
  10. 10器件和文档支持
    1. 10.1 器件支持
      1. 10.1.1 第三方产品免责声明
      2. 10.1.2 开发支持
        1. 10.1.2.1 使用 WEBENCH® 工具创建定制设计
    2. 10.2 接收文档更新通知
    3. 10.3 社区资源
    4. 10.4 商标
    5. 10.5 静电放电警告
    6. 10.6 Glossary
  11. 11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

7.3.7 Short-Circuit Condition

Due to the inherent nature of boost regulators, when the output is shorted (see Figure 23 ), current flows directly from the input, through the inductor and the diode, to the output, bypassing the switch. The current limit of the switch does not limit the output current for the entire circuit. To protect the load and prevent damage to the switch, the current must be externally limited, either by the input supply or at the output with an external current limit circuit. The external limit should be set to the maximum switch current of the device, which is 5 A.

In a flyback regulator application (Figure 24 ), using the standard transformers, the LM2588 survives a short circuit to the main output. When the output voltage drops to 80% of its nominal value, the frequency will drop to 25 kHz. With a lower frequency, off times are larger. With the longer off times, the transformer can release all of its stored energy before the switch turns back on. Hence, the switch turns on initially with zero current at its collector. In this condition, the switch current limit will limit the peak current, saving the device.

LM2588 01242056.pngFigure 23. Boost Regulator
LM2588 01242057.pngFigure 24. Flyback Regulator