SNVS039J June   2000  – April 2015 LM1086

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 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 Ripple Rejection
      2. 7.3.2 Load Regulation
      3. 7.3.3 Overload Recovery
    4. 7.4 Device Functional Modes
      1. 7.4.1 Output Voltage
      2. 7.4.2 Stability Consideration
      3. 7.4.3 Protection Diodes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1  1.2-V to 15-V Adjustable Regulator
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
      2. 8.2.2  Adjustable at 5 V
      3. 8.2.3  5-V Regulator with Shutdown
      4. 8.2.4  Battery Charger
      5. 8.2.5  Adjustable Fixed Regulator
      6. 8.2.6  Regulator With Reference
      7. 8.2.7  High Current Lamp Driver Protection
      8. 8.2.8  Battery Backup Regulated Supply
      9. 8.2.9  Ripple Rejection Enhancement
      10. 8.2.10 Automatic Light Control
      11. 8.2.11 Remote Sensing
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Development Support
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.1 Overview

A basic functional diagram for the LM1086-ADJ (excluding protection circuitry) is shown in Figure 13. The topology is basically that of the LM317 except for the pass transistor. Instead of a Darlingtion NPN with its two diode voltage drop, the LM1086 uses a single NPN. This results in a lower dropout voltage. The structure of the pass transistor is also known as a quasi LDO. The advantage of a quasi LDO over a PNP LDO is its inherently lower quiescent current. The LM1086 is specified to provide a minimum dropout voltage of 1.5V over temperature, at full load.

LM1086 10094865.pngFigure 13. Basic Functional Block Diagram