SNVSCM7A December   2023  – May 2026 LMR38015-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 and Synchronization (RT/SYNC)
      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 Auto Mode
      2. 7.4.2 Forced PWM Operation
      3. 7.4.3 Dropout
      4. 7.4.4 Minimum Switch On Time
  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 Choosing the Switching Frequency
        3. 8.2.2.3 FB for Adjustable Output
        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 CBOOT
        8. 8.2.2.8 External UVLO
        9. 8.2.2.9 Maximum Ambient Temperature
      3. 8.2.3 Application Curves
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
        1. 8.5.1.1 Ground and Thermal Considerations
      2. 8.5.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
      2. 9.1.2 Development Support
        1. 9.1.2.1 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

8.2.3 Application Curves

Unless otherwise specified the following conditions apply: VIN = 48V, L = 27µH , TA = 25°C.

LMR38015-Q1 Start-Up by VIN
LMR38015-Q1 VOUT = 5V 400kHz
Figure 8-3 Start-Up by VIN
LMR38015-Q1 PFM Switching
LMR38015-Q1 VOUT = 5V

AC Coupled

 No Load
Figure 8-5 PFM Switching
LMR38015-Q1 Short Circuit Applied
LMR38015-Q1 VOUT = 5V 1A to Short
Figure 8-7 Short Circuit Applied
LMR38015-Q1 Start-Up With Prebias
LMR38015-Q1 VOUT = 5V

Bias to 3V

 No Load
Figure 8-9 Start-Up With Prebias
LMR38015-Q1 Load Transient
LMR38015-Q1 VOUT = 5V

(AC Coupled)

 400kHz
150mA to 1350mA at 200mA/µs
Figure 8-11 Load Transient
LMR38015-Q1 5V Load Regulation
LMR38015-Q1 VOUT = 5V

PFM Version

 400kHz
Figure 8-13 5V Load Regulation
LMR38015-Q1 Typical CISPR 25 Conducted EMI 150kHz - 108MHz Green: Average Detect, Blue = Peak Detect
VIN = 48V VOUT = 5V Fsw = 400kHz
Load = 1.5A
Figure 8-15 Typical CISPR 25 Conducted EMI 150kHz - 108MHz Green: Average Detect, Blue = Peak Detect
LMR38015-Q1 Start-Up by EN
LMR38015-Q1 VOUT = 5V 400kHz
Figure 8-4 Start-Up by EN
LMR38015-Q1 Full Load Switching
LMR38015-Q1 VOUT = 5V

AC Coupled

 400kHz
Figure 8-6 Full Load Switching
LMR38015-Q1 Short-Circuit Recovery
LMR38015-Q1 VOUT = 5V Short Recovery
Figure 8-8 Short-Circuit Recovery
LMR38015-Q1 Frequency Synchronization
LMR38015-Q1 VOUT = 5V 400kHz
Figure 8-10 Frequency Synchronization
LMR38015-Q1 Line Transient
LMR38015-Q1 VOUT = 5V

(AC Coupled)

 400kHz
10V to 70V at 200V/ms
Figure 8-12 Line Transient
LMR38015-Q1 12V Load Regulation
LMR38015-Q1 VOUT = 12V

PFM Version

 400kHz
Figure 8-14 12V Load Regulation
LMR38015-Q1 Typical EMI Input Filter
Ferrite Bead FBMH3225HM102NT
Figure 8-16 Typical EMI Input Filter