SNVS775K March 2000  – April 2016 LM317L-N


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1Absolute Maximum Rating
    2. 6.2ESD Ratings
    3. 6.3Recommended Operating Conditions
    4. 6.4Thermal Information
    5. 6.5Electrical Characteristics
    6. 6.6Typical Characteristics
  7. Detailed Description
    1. 7.1Overview
    2. 7.2Functional Block Diagram
    3. 7.3Feature Description
      1. 7.3.1Load Regulation
    4. 7.4Device Functional Modes
      1. 7.4.1External Capacitors
      2. 7.4.2Protection Diodes
      3. 7.4.3Protection Diodes
      4. 7.4.4DSBGA Light Sensitivity
  8. Application and Implementation
    1. 8.1Application Information
    2. 8.2Typical Applications
      1. 8.2.1 1.25-V to 25-V Adjustable Regulator
        1. Requirements
        2. Design Procedure
        3. Curve
      2. 8.2.2 Digitally-Selected Outputs
      3. 8.2.3 High Gain Amplifier
      4. 8.2.4 Adjustable Current Limiter
      5. 8.2.5 Precision Current Limiter
      6. 8.2.6 Slow Turnon 15-V Regulator
      7. 8.2.7 Adjustable Regulator With Improved Ripple Rejection
      8. 8.2.8 High Stability 10-V Regulator
      9. 8.2.9 Adjustable Regulator With Current Limiter
      10. 8.2.100-V to 30-V Regulator
      11. 8.2.11Regulator With 15-mA Short-Circuit Current
      12. 8.2.12Power Follower
      13. 8.2.13Adjusting Multiple On-Card Regulators With Single Control
      14. 8.2.14100-mA Current Regulator
      15. to 12-V Regulator With Minimum Program Current
      16. 8.2.1650-mA Constant Current Battery Charger for Nickel-Cadmium Batteries
      17. 8.2.175-V Logic Regulator With Electronic Shutdown
      18. 8.2.18Current-Limited 6-V Charger
      19. 8.2.19Short Circuit-Protected 80-V Supply
      20. 8.2.20Basic High-Voltage Regulator
      21. 8.2.21Precision High-Voltage Regulator
      22. 8.2.22Tracking Regulator
      23. 8.2.23Regulator With Trimmable Output Voltage
      24. 8.2.24Precision Reference With Short-Circuit Proof Output
      25. 8.2.25Fully-Protected (Bulletproof) Lamp Driver
      26. 8.2.26Lamp Flasher
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1Layout Guidelines
    2. 10.2Layout Examples
    3. 10.3Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1Documentation Support
      1. 11.1.1Related Documentation
    2. 11.2Community Resources
    3. 11.3Trademarks
    4. 11.4Electrostatic Discharge Caution
    5. 11.5Glossary
  12. 12Mechanical, Packaging, and Orderable Information


机械数据 (封装 | 引脚)

1 Features

  • Adjustable Output Down to 1.2 V
  • 100-mA Output Current
  • Line Regulation Typically 0.01% V
  • Load Regulation Typically 0.1%
  • Current Limit Constant With Temperature
  • Eliminates the Need to Stock Many Voltages
  • Standard 3-Lead Transistor Package
  • 80-dB Ripple Rejection
  • Available in 3-Pin TO-92, 8-Pin SOIC, or 6-pin DSBGA Packages
  • Output is Short-Circuit Protected
  • See AN-1112 (SNVA009) for DSBGA Considerations

2 Applications

  • Automotive LED Lighting
  • Battery Chargers
  • Post Regulation for Switching Supplies
  • Constant-Current Regulators
  • Microprocessor Supplies

Schematic Diagram

LM317L-N 906401.png
Full output current not available at high input-output voltages

†Optional—improves transient response

*Needed if device is more than 6 inches from filter capacitors

LM317L-N 906446.png

3 Description

The LM317L-N is an adjustable 3-terminal positive voltage regulator capable of supplying 100 mA over a 1.2-V to 37-V output range. The LM317L-N is easy to use and requires only two external resistors to set the output voltage. Both line and load regulation are better than standard fixed regulators. The LM317L-N is available packaged in a standard, easy-to-use
TO-92 transistor package.

In addition to higher performance than fixed regulators, the LM317L-N offers full overload protection. Included on the chip are current limit, thermal overload protection, and safe area protection. All overload protection circuitry remains fully functional even if the adjustment terminal is disconnected.

Normally, no capacitors are required unless the device is situated more than 6 inches from the input filter capacitors, in which case an input bypass is required. An optional output capacitor can be added to improve transient response. The adjustment terminal can be bypassed to achieve very high ripple rejection ratios, which are difficult to achieve with standard 3-terminal regulators.

Besides replacing fixed regulators, the LM317L-N is useful in a wide variety of other applications. Because the regulator is floating and sees only the input-to-output differential voltage, supplies of several hundred volts can be regulated, provided the maximum input-to-output differential is not exceeded.

The LM317L-N makes a simple adjustable switching regulator, a programmable output regulator, or by connecting a fixed resistor between the adjustment and output, the LM317L-N can be used as a precision current regulator. Supplies with electronic shutdown can be achieved by clamping the adjustment terminal to ground which programs the output to 1.2 V, where most loads draw little current.

The LM317L-N is available in a standard 3-pin TO-92 transistor package, the 8-pin SOIC package, and 6-pin DSBGA package. The LM317L-N is rated for operation over a −40°C to 125°C range.

Device Information(1)

LM317L-NTO-92 (3)4.30 mm × 4.30 mm
SOIC (8)3.91 mm × 4.90 mm
DSBGA (6)1.68 mm × 1.019 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

4 Revision History

Changes from J Revision (March 2013) to K Revision

  • Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section. Go

Changes from I Revision (March 2013) to J Revision

  • Changed layout of National Data Sheet to TI formatGo