SLUSEG8B October   2021  – February 2022 LMR54406 , LMR54410

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 System Characteristics
    8. 7.8 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Fixed Frequency Peak Current Mode Control
      2. 8.3.2 Adjustable Output Voltage
      3. 8.3.3 Enable
      4. 8.3.4 Minimum ON Time, Minimum OFF Time, and Frequency Foldback
      5. 8.3.5 Bootstrap Voltage
      6. 8.3.6 Overcurrent and Short Circuit Protection
      7. 8.3.7 Soft Start
      8. 8.3.8 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Active Mode
      3. 8.4.3 CCM Mode
      4. 8.4.4 Light Load Operation (PFM Version)
      5. 8.4.5 Light-Load Operation (FPWM Version)
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Output Voltage Set-Point
        2. 9.2.2.2 Switching Frequency
        3. 9.2.2.3 Inductor Selection
        4. 9.2.2.4 Output Capacitor Selection
        5. 9.2.2.5 Input Capacitor Selection
        6. 9.2.2.6 Bootstrap Capacitor
        7. 9.2.2.7 Undervoltage Lockout Set-Point
        8. 9.2.2.8 Replacing Non Sync Converter
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Compact Layout for EMI Reduction
      2. 11.1.2 Feedback Resistors
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

Description

The LMR544xx is a wide-VIN, easy-to-use synchronous buck converter capable of driving up to 1-A and 0.6-A load current. With a wide input range of 4 V to 36 V, the device is suitable for a wide range of industrial applications for power conditioning from an unregulated source.

The LMR544xx operates at 1.1-MHz switching frequency to support use of relatively small inductors for an optimized solution size. It has a PFM version to realize high efficiency at light load and a FPWM version to achieve constant frequency and small output voltage ripple over the full load range. Soft-start and compensation circuits are implemented internally, which allow the device to be used with minimal external components.

The device has built-in protection features, such as cycle-by-cycle current limit, hiccup mode short-circuit protection, and thermal shutdown in case of excessive power dissipation.

Device Information
PART NUMBERPACKAGE(1)BODY SIZE (NOM)
LMR54410SOT-23 (6)2.90 mm × 1.60 mm
LMR54406
For all available packages, see the orderable addendum at the end of the data sheet.
GUID-FE4A0CA2-50A1-43E6-B5CD-5B8B6AC6E250-low.gifSimplified Schematic
GUID-20211116-SS0I-QMPV-RNCZ-RV6HR21BZ2GB-low.pngEfficiency Versus Output Current;
VOUT = 5 V, 1100 kHz