SNVSC00A February   2023  – January 2025 LM5148-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Description (continued)
  6. 5 Pin Configuration and Functions
    1. 5.1 Wettable Flanks
  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 Thermal Information
    6. 6.6 Electrical 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  Input Voltage Range (VIN)
      2. 7.3.2  High-Voltage Bias Supply Regulator (VCC, VCCX, VDDA)
      3. 7.3.3  Precision Enable (EN)
      4. 7.3.4  Power-Good Monitor (PG)
      5. 7.3.5  Switching Frequency (RT)
      6. 7.3.6  Dual Random Spread Spectrum (DRSS)
      7. 7.3.7  Soft Start
      8. 7.3.8  Output Voltage Setpoint (FB)
      9. 7.3.9  Minimum Controllable On Time
      10. 7.3.10 Error Amplifier and PWM Comparator (FB, EXTCOMP)
      11. 7.3.11 Slope Compensation
      12. 7.3.12 Inductor Current Sense (ISNS+, VOUT)
        1. 7.3.12.1 Shunt Current Sensing
        2. 7.3.12.2 Inductor DCR Current Sensing
      13. 7.3.13 Hiccup Mode Current Limiting
      14. 7.3.14 High-Side and Low-Side Gate Drivers (HO, LO)
      15. 7.3.15 Output Configurations (CNFG)
      16. 7.3.16 Single-Output Dual-Phase Operation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Sleep Mode
      2. 7.4.2 Pulse Frequency Modulation and Synchronization (PFM/SYNC)
      3. 7.4.3 Thermal Shutdown
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Power Train Components
        1. 8.1.1.1 Buck Inductor
        2. 8.1.1.2 Output Capacitors
        3. 8.1.1.3 Input Capacitors
        4. 8.1.1.4 Power MOSFETs
        5. 8.1.1.5 EMI Filter
      2. 8.1.2 Error Amplifier and Compensation
    2. 8.2 Typical Applications
      1. 8.2.1 Design 1 – High Efficiency 2.1MHz Synchronous Buck Regulator
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design with WEBENCH® Tools
          2. 8.2.1.2.2 Custom Design with Excel Quickstart Tool
          3. 8.2.1.2.3 Buck Inductor
          4. 8.2.1.2.4 Current-Sense Resistance
          5. 8.2.1.2.5 Output Capacitors
          6. 8.2.1.2.6 Input Capacitors
          7. 8.2.1.2.7 Frequency Set Resistor
          8. 8.2.1.2.8 Feedback Resistors
          9. 8.2.1.2.9 Compensation Components
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Design 2 – High Efficiency 48-V to 12-V 400-kHz Synchronous Buck Regulator
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curves
      3. 8.2.3 Design 3 – High Efficiency 440-kHz Synchronous Buck Regulator
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
        3. 8.2.3.3 Application Curves
      4. 8.2.4 Design 4 – Dual-Phase 400-kHz 20-A Synchronous Buck Regulator
        1. 8.2.4.1 Design Requirements
        2. 8.2.4.2 Detailed Design Procedure
        3. 8.2.4.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Power Stage Layout
        2. 8.4.1.2 Gate-Drive Layout
        3. 8.4.1.3 PWM Controller Layout
        4. 8.4.1.4 Thermal Design and Layout
        5. 8.4.1.5 Ground Plane Design
      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
        1. 9.2.1.1 PCB Layout Resources
        2. 9.2.1.2 Thermal Design Resources
    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

4 Description (continued)

Additional features of the LM5148-Q1 include 150°C maximum junction temperature operation, user-selectable diode emulation for lower current consumption at light-load conditions, open-drain power-good flag for fault reporting and output monitoring, precision enable input, monotonic start-up into prebiased load, integrated VCC bias supply regulator, internal 3ms soft-start time, and thermal shutdown protection with automatic recovery.

The LM5148-Q1 controller comes in 3.5mm × 5.5mm, 24-pin VQFN and a 19-pin VQFN, 4.50mm × 3.5mm thermally enhanced packages with wettable flank pins to facilitate optical inspection during manufacturing. For high voltage applications that require additional pin spacing between low voltage pins and high voltage pins, the pin spacing was increased to 0.6mm by removing a pin. To increase the spacing from VIN to the exposed pad, the exposed pad was reduced to 1.7mm × 2.3mm.