SNVSBS6B January   2023  – January 2024 LMR38020-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

Package Options

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

8.2.3 Application Curves

Unless otherwise specified the following conditions apply: VIN = 48 V, L = 15 µH , TA = 25°C.

GUID-20211111-SS0I-B5BL-WBGS-H4VTF74J7SGH-low.png
LMR38020-Q1VOUT = 5 V400 kHz
Figure 8-3 Start-Up by VIN
GUID-20211112-SS0I-9Q1B-L0HK-SHCHNRNCB188-low.png
LMR38020-Q1VOUT = 5 V

AC Coupled

No Load
Figure 8-5 PFM Switching
GUID-20211111-SS0I-VLTN-KBTV-4Q5Q2RPPB05L-low.png
LMR38020-Q1VOUT = 5 V2 A to Short
Figure 8-7 Short Circuit Applied
GUID-20211112-SS0I-WV9P-5NPN-QM831BF3KHB3-low.png
LMR38020-Q1 FPWMVOUT = 5 V

Bias to 3 V

No Load
Figure 8-9 Start-Up with Prebias
GUID-20211112-SS0I-Z31X-NXNC-CJWVMR25T1ZJ-low.png
LMR38020-Q1VOUT = 5 V

(AC Coupled)

400 kHz
200 mA to 1.8 A at 200 mA/µs
Figure 8-11 Load Transient
GUID-20211109-SS0I-M57Z-H0GF-1MGN74CDQ4JP-low.svg
LMR38020-Q1VOUT = 5 V

PFM Version

400 kHz
Figure 8-13 5-V Load Regulation
GUID-20211112-SS0I-SX2T-1FGD-MG9PSJ3GXT1Q-low.png
LMR38020-Q1VOUT = 5 V400 kHz
Figure 8-4 Start-Up by EN
GUID-20211111-SS0I-2MWJ-CW3J-SPT7NZ3BTJMJ-low.png
LMR38020-Q1VOUT = 5 V

AC Coupled

400 kHz
Figure 8-6 Full Load Switching
GUID-20211112-SS0I-ZFCP-98PG-WX2CWZLPJJV7-low.png
LMR38020-Q1VOUT = 5 VShort Recovery
Figure 8-8 Short-Circuit Recovery
GUID-20211112-SS0I-VK3K-SH8T-QTFB2VX8DZR3-low.png
LMR38020-Q1VOUT = 5 V400 kHz
Figure 8-10 Frequency Synchronization
GUID-20211115-SS0I-WQDW-DL1C-FZXN5GTF42P7-low.png
LMR38020-Q1VOUT = 5 V

(AC Coupled)

400 kHz
10 V to 70 V at 200 V/ms
Figure 8-12 Line Transient
GUID-20211109-SS0I-QVZB-XSHB-QDJRNRRTLWWM-low.svg
LMR38020-Q1VOUT = 12 V

PFM Version

400 kHz
Figure 8-14 12-V Load Regulation