SNVS276I April   2004  – February 2019 LM2743

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Diagram
  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  Start Up and Soft-Start
      2. 7.3.2  Normal Operation
      3. 7.3.3  Tracking a Voltage Level
      4. 7.3.4  Tracking Voltage Slew Rate
      5. 7.3.5  Sequencing
      6. 7.3.6  SD Pin Impedance
      7. 7.3.7  MOSFET Gate Drivers
      8. 7.3.8  Power Good Signal
      9. 7.3.9  UVLO
      10. 7.3.10 Current Limit
      11. 7.3.11 Foldback Current Limit
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Synchronous Buck Converter Typical Application using LM2743
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2 Duty Cycle Calculation
          3. 8.2.1.2.3 Input Capacitor
          4. 8.2.1.2.4 Output Inductor
          5. 8.2.1.2.5 Output Capacitor
          6. 8.2.1.2.6 MOSFETs
          7. 8.2.1.2.7 Support Components
          8. 8.2.1.2.8 Control Loop Compensation
          9. 8.2.1.2.9 Efficiency Calculations
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Example Circuit 1
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Bill of Materials
      3. 8.2.3 Example Circuit 2
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
        3. 8.2.3.3 Bill of Materials
      4. 8.2.4 Example Circuit 3
        1. 8.2.4.1 Design Requirements
        2. 8.2.4.2 Detailed Design Procedure
        3. 8.2.4.3 Bill of Materials
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Custom Design With WEBENCH® Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

10.1 Layout Guidelines

In a buck regulator, the primary switching loop consists of the input capacitor and MOSFET switches. Minimixing the area of this loop reduces the stray inductance, and minimizes noise and possible erratic operation. High quality input capacitors should be placed as close as possible to the MOSFET switches, with the positive side of the input capacitor connected directly to the high-side MOSFET drain, and the ground side of the capacitor connected as close as possible to the low-side MOSFET switch ground connection. Connect all of the low power ground connections directly to the SGND pin. Connect the VCC capacitor directly to the PGND pin.