SLUSFM2 August   2024 LMR51440-Q1 , LMR51450-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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 System Characteristics
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Fixed Frequency Peak Current Mode Control
      2. 7.3.2  Adjustable Output Voltage
      3. 7.3.3  Enable
      4. 7.3.4  Switching Frequency
      5. 7.3.5  Power-Good Flag Output
      6. 7.3.6  Minimum ON-Time, Minimum OFF-Time, and Frequency Foldback
      7. 7.3.7  Bootstrap Voltage
      8. 7.3.8  Overcurrent and Short-Circuit Protection
      9. 7.3.9  Soft Start
      10. 7.3.10 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Active Mode
      3. 7.4.3 CCM Mode
      4. 7.4.4 Light-Load Operation (PFM Version)
      5. 7.4.5 Light-Load Operation (FPWM Version)
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Output Voltage Set-Point
        3. 8.2.2.3 Switching Frequency
        4. 8.2.2.4 Inductor Selection
        5. 8.2.2.5 Output Capacitor Selection
        6. 8.2.2.6 Input Capacitor Selection
        7. 8.2.2.7 Bootstrap Capacitor
        8. 8.2.2.8 Undervoltage Lockout Setpoint
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Compact Layout for EMI Reduction
        2. 8.4.1.2 Feedback Resistors
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
        1. 9.1.1.1 Custom Design With WEBENCH® Tools
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Tape and Reel Information

7.4.1 Shutdown Mode

The EN pin provides electrical ON and OFF control for the LMR514x0-Q1. When VEN is below 0.8V, the device is in shutdown mode. The LMR514x0-Q1 also employs VIN undervoltage lockout protection (UVLO). If VIN voltage is below the UVLO threshold 3.4V, the converter is turned off.