SNVS771D May   1998  – May 2025 LM138 , LM338

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 Recommended Operating Conditions
    3. 5.3 Thermal Information
    4. 5.4 Electrical Characteristics: LM138
    5. 5.5 Electrical Characteristics: LM338
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 NPN Darlington Output Drive
      2. 6.3.2 Overload Block
      3. 6.3.3 Programmable Feedback
    4. 6.4 Device Functional Modes
      1. 6.4.1 Normal Operation
      2. 6.4.2 Operation With Low Input Voltage
      3. 6.4.3 Operation at Light Loads
      4. 6.4.4 Operation in Self Protection
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Constant 5-V Regulator
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 External Capacitors
          2. 7.2.1.2.2 Load Regulation
          3. 7.2.1.2.3 Protection Diodes
        3. 7.2.1.3 Application Curves
    3. 7.3 System Examples
    4. 7.4 Power Supply Recommendations
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
      2. 7.5.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

5.3 Thermal Information

THERMAL METRIC(1) LM338 LM338 UNIT
NDS (TO-CAN) NDE (TO-220) NDS (TO-CAN)
2 PINS 3 PINS 2 PINS
RθJA Junction-to-ambient thermal resistance 35 22.9 35 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 1 15.7 1 °C/W
RθJB Junction-to-board thermal resistance — 4.1 — °C/W
ψJT Junction-to-top characterization parameter — 2.1 — °C/W
ψJB Junction-to-board characterization parameter — 4.1 — °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance — 0.7 — °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application note.