SLVS044Y September   1997  – April 2020 LM317

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Battery-Charger Circuit
  4. 4 Revision History
  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. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.3.7 50-mA Constant-Current Battery-Charger Circuit

The current limit operation mode can be used to trickle charge a battery at a fixed current. ICHG = 1.25 V ÷ 24 Ω. VI should be greater than VBAT + 4.25 V. (1.25 V [VREF] + 3 V [headroom])

LM317 appin9_lvs044.gifFigure 18. 50-mA Constant-Current Battery-Charger Circuit