ZHCSH33Y September   1997  – April 2020 LM317

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      电池充电器电路
  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 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 NPN Darlington Output Drive
      2. 8.3.2 Overload Block
      3. 8.3.3 Programmable Feedback
    4. 8.4 Device Functional Modes
      1. 8.4.1 Normal Operation
      2. 8.4.2 Operation With Low Input Voltage
      3. 8.4.3 Operation at Light Loads
      4. 8.4.4 Operation In Self Protection
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1  0-V to 30-V Regulator Circuit
      2. 9.3.2  Adjustable Regulator Circuit With Improved Ripple Rejection
      3. 9.3.3  Precision Current-Limiter Circuit
      4. 9.3.4  Tracking Preregulator Circuit
      5. 9.3.5  1.25-V to 20-V Regulator Circuit With Minimum Program Current
      6. 9.3.6  Battery-Charger Circuit
      7. 9.3.7  50-mA Constant-Current Battery-Charger Circuit
      8. 9.3.8  Slow Turn-On 15-V Regulator Circuit
      9. 9.3.9  AC Voltage-Regulator Circuit
      10. 9.3.10 Current-Limited 6-V Charger Circuit
      11. 9.3.11 Adjustable 4-A Regulator Circuit
      12. 9.3.12 High-Current Adjustable Regulator Circuit
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12器件和文档支持
    1. 12.1 接收文档更新通知
    2. 12.2 支持资源
    3. 12.3 商标
    4. 12.4 静电放电警告
    5. 12.5 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

9.3.5 1.25-V to 20-V Regulator Circuit With Minimum Program Current

Because the value of VREF is constant, the value of R1 determines the amount of current that flows through R1 and R2. The size of R2 determines the IR drop from ADJUSTMENT to GND. Higher values of R2 translate to higher VOUT.

Equation 2. LM317 lm317l_appeqn.gif
Equation 3. LM317 equation1_SLVS044X.gif
LM317 appin6_lvs044.gifFigure 16. 1.25-V to 20-V Regulator Circuit With Minimum Program Current