SNVSCJ0A November   2023  – February 2024 LMR38025-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 = 48V, L = 12µH , TA = 25°C.

GUID-20230929-SS0I-SZLC-VGXR-CP8JCTKGNFT9-low.svg

12 V

LMR38025-Q1		 VOUT = 5V 400kHz

2.0ms/DIV

Figure 8-3 Start-Up by VIN
GUID-20230929-SS0I-12ND-HNJR-0FXSDWTDW5VN-low.svg
LMR38025-Q1 VOUT = 5V

AC Coupled

 No Load

8.0ms/DIV

Figure 8-5 PFM Switching
GUID-20230929-SS0I-WJB1-LNKS-8F1LZX1P2MGC-low.svg
LMR38025-Q1 VOUT = 5V 2.5A to Short

40ms/DIV

Figure 8-7 Short Circuit Applied
GUID-20230929-SS0I-M5FP-JRSH-VLQD0GHPVQDD-low.svg
LMR38025-Q1 VOUT = 5V No Load

4.0ms/DIV

Figure 8-9 Start-Up With Prebias
GUID-20230929-SS0I-KTTQ-GJNJ-T0FWZRGFX1DZ-low.svg
LMR38025-Q1(PFM) VOUT = 5V

(AC Coupled)

 400kHz,100µs/DIV
250mA to 2.25A at 200mA/µs
Figure 8-11 Load Transient
GUID-20240201-SS0I-9ZK2-R3LR-8GNXH4G0K7HV-low.svg
LMR38025-Q1 VOUT = 5V

PFM Version

 400kHz
Figure 8-13 5V Load Regulation
GUID-20231018-SS0I-TPXL-DPVC-WBH4RW9P6DXQ-low.svg
VIN = 48V VOUT = 5V Fsw = 400kHz
Figure 8-15 Typical CISPR 25 Conducted EMI 150kHz - 108MHz Green: Average Detect, Blue = Peak Detect
GUID-20230929-SS0I-2GBL-D5WM-JJGZJVHCJFGG-low.svg
LMR38025-Q1 VOUT = 5V 400kHz

2.0ms/DIV

Figure 8-4 Start-Up by EN
GUID-20230929-SS0I-CPK0-DZ6W-3CL7FJBH2X93-low.svg
LMR38025-Q1 VOUT = 5V

AC Coupled

 400kHz

1.0µs/DIV

Figure 8-6 Full Load Switching
GUID-20230929-SS0I-JXBX-LPTN-BCVN0Z3QDBMF-low.svg
LMR38025-Q1 VOUT = 5V Short Recovery

40ms/DIV

Figure 8-8 Short-Circuit Recovery
GUID-20230929-SS0I-KZTJ-TJRS-8DKLPSNTSRPQ-low.svg
LMR38025-Q1 VOUT = 5V 400kHz

2µs/DIV

Figure 8-10 Frequency Synchronization
GUID-20230929-SS0I-XQDW-VRZD-BGMSMGFFL0H7-low.svg
LMR38025-Q1(PFM) VOUT = 5V

(AC Coupled)

 400kHz

800µs/DIV

10V to 70V at 200V/ms
Figure 8-12 Line Transient
GUID-20240201-SS0I-JP7T-CRKW-4SFBJJVCXQ3N-low.svg
LMR38025-Q1 VOUT = 12V

PFM Version

 400kHz
Figure 8-14 12V Load Regulation
GUID-20231018-SS0I-ZN3W-BHHP-WKTGR46SZMKW-low.svg
Ferrite Bead FBMH3225HM102NT
Figure 8-16 Typical EMI Input Filter