SNOS491D February   2000  – September 2018 LM4051-N

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1. 1.2 VREF Simplified Schematic
      2.      Adjustable Reference Simplified Schematic
  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 LM4051-1.2 Electrical Characteristics
    6. 6.6 LM4051-ADJ Electrical Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
      1. 8.4.1 LM4051-N - 1.2 V
      2. 8.4.2 LM4051-N - ADJ
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Shunt Regulator
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Adjustable Shunt Regulator
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
    3. 9.3 System Examples
  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 Community 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

9.2.1.2 Detailed Design Procedure

The resistor RS must be selected such that current, IR, will remain in the operational region of the part for the entire VIN range and load current range. The two extremes to consider are VIN at its maximum, and the load at its minimum, where RS must be large enough to main IR < IRMAX. For most desigins, 0.1 mA ≤ IR≤ 1 mA is a good starting point.

Use cross and cross to set RS between RS_MIN and RS_MAX.

Equation 5. LM4051-N equations_01_snos633.gif
Equation 6. LM4051-N equations_02_snos633.gif