SLUSFM4 September   2024 LMR51425 , LMR51435

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

Package Options

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

6.7 Typical Characteristics

VIN = 12V, fSW= 500kHz,TA = 25°C, unless otherwise specified.

LMR51425 LMR51435 5V Efficiency versus Load Current
fSW = 500kHzVOUT = 5VLMR51435
Figure 6-1 5V Efficiency versus Load Current
LMR51425 LMR51435 3.3V Efficiency versus Load Current
fSW = 500kHzVOUT = 3.3VLMR51435
Figure 6-3 3.3V Efficiency versus Load Current
LMR51425 LMR51435 5V Efficiency versus Load Current
fSW = 500kHzVOUT = 5VLMR51425
Figure 6-5 5V Efficiency versus Load Current
LMR51425 LMR51435 3.3V Efficiency versus Load Current
fSW = 500kHzVOUT = 3.3VLMR51425
Figure 6-7 3.3V Efficiency versus Load Current
LMR51425 LMR51435 5V Load Regulation
VOUT = 5VPFM version
Figure 6-9 5V Load Regulation
LMR51425 LMR51435 5V Dropout
VOUT = 5VPFM version
Figure 6-11 5V Dropout
LMR51425 LMR51435 Non-Switching Input Supply Current
Figure 6-13 Non-Switching Input Supply Current
LMR51425 LMR51435 Reference VoltageFigure 6-15 Reference Voltage
LMR51425 LMR51435 LMR51435 High Side and Low Side Current LimitsFigure 6-17 LMR51435 High Side and Low Side Current Limits
LMR51425 LMR51435 5V Efficiency versus Load Current
fSW = 1MHzVOUT = 5VLMR51435
Figure 6-2 5V Efficiency versus Load Current
LMR51425 LMR51435 3.3V Efficiency versus Load Current
fSW = 1MHzVOUT = 3.3VLMR51435
Figure 6-4 3.3V Efficiency versus Load Current
LMR51425 LMR51435 5V Efficiency versus Load Current
fSW = 1MHzVOUT = 5VLMR51425
Figure 6-6 5V Efficiency versus Load Current
LMR51425 LMR51435 3.3V Efficiency versus Load Current
fSW = 1MHzVOUT = 3.3VLMR51425
Figure 6-8 3.3V Efficiency versus Load Current
LMR51425 LMR51435 3.3V Load Regulation
VOUT = 3.3VPFM version
Figure 6-10 3.3V Load Regulation
LMR51425 LMR51435 3.3V Dropout
VOUT = 3.3VPFM version
Figure 6-12 3.3V Dropout
LMR51425 LMR51435 VIN UVLO
Figure 6-14 VIN UVLO
LMR51425 LMR51435 High Side and Low Side Switches RDS_ONFigure 6-16 High Side and Low Side Switches RDS_ON
LMR51425 LMR51435 LMR51425 High Side and Low Side Current LimitsFigure 6-18 LMR51425 High Side and Low Side Current Limits