SNVSBV4A December   2020  – January 2023 LM5149

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Active EMI Filter
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Input Voltage Range (VIN)
      2. 8.3.2  High-Voltage Bias Supply Regulator (VCC, VCCX, VDDA)
      3. 8.3.3  Precision Enable (EN)
      4. 8.3.4  Power-Good Monitor (PG)
      5. 8.3.5  Switching Frequency (RT)
      6. 8.3.6  Active EMI Filter
      7. 8.3.7  Dual Random Spread Spectrum (DRSS)
      8. 8.3.8  Soft Start
      9. 8.3.9  Output Voltage Setpoint (FB)
      10. 8.3.10 Minimum Controllable On Time
      11. 8.3.11 Error Amplifier and PWM Comparator (FB, EXTCOMP)
      12. 8.3.12 Slope Compensation
      13. 8.3.13 Inductor Current Sense (ISNS+, VOUT)
        1. 8.3.13.1 Shunt Current Sensing
        2. 8.3.13.2 Inductor DCR Current Sensing
      14. 8.3.14 Hiccup Mode Current Limiting
      15. 8.3.15 High-Side and Low-Side Gate Drivers (HO, LO)
      16. 8.3.16 Output Configurations (CNFG)
      17. 8.3.17 Single-Output Dual-Phase Operation
    4. 8.4 Device Functional Modes
      1. 8.4.1 Sleep Mode
      2. 8.4.2 Pulse Frequency Modulation and Synchronization (PFM/SYNC)
      3. 8.4.3 Thermal Shutdown
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Power Train Components
        1. 9.1.1.1 Buck Inductor
        2. 9.1.1.2 Output Capacitors
        3. 9.1.1.3 Input Capacitors
        4. 9.1.1.4 Power MOSFETs
        5. 9.1.1.5 EMI Filter
        6. 9.1.1.6 Active EMI Filter
      2. 9.1.2 Error Amplifier and Compensation
    2. 9.2 Typical Applications
      1. 9.2.1 Design 1 – High-Efficiency 2.1-MHz Synchronous Buck Regulator
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 9.2.1.2.2 Custom Design With Excel Quickstart Tool
          3. 9.2.1.2.3 Buck Inductor
          4. 9.2.1.2.4 Current-Sense Resistance
          5. 9.2.1.2.5 Output Capacitors
          6. 9.2.1.2.6 Input Capacitors
          7. 9.2.1.2.7 Frequency Set Resistor
          8. 9.2.1.2.8 Feedback Resistors
          9. 9.2.1.2.9 Compensation Components
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Design 2 – High Efficiency 48-V to 12-V 400-kHz Synchronous Buck Regulator
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
      3. 9.2.3 Design 3 – High Efficiency 440-kHz Synchronous Buck Regulator
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 Application Curves
      4. 9.2.4 Design 4 – Dual-Phase 400-kHz 20-A Synchronous Buck Regulator
        1. 9.2.4.1 Design Requirements
        2. 9.2.4.2 Detailed Design Procedure
        3. 9.2.4.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 Power Stage Layout
        2. 9.4.1.2 Gate-Drive Layout
        3. 9.4.1.3 PWM Controller Layout
        4. 9.4.1.4 Active EMI Layout
        5. 9.4.1.5 Thermal Design and Layout
        6. 9.4.1.6 Ground Plane Design
      2. 9.4.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
        1. 10.1.1.1 Custom Design With WEBENCH® Tools
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
        1. 10.2.1.1 PCB Layout Resources
        2. 10.2.1.2 Thermal Design Resources
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Functional Safety-Capable
  • Two integrated EMI mitigation mechanisms
    • Active EMI Filter for enhanced EMI performance at lower frequencies
    • Selectable dual random spread spectrum (DRSS) for enhanced EMI performance across low and high-frequency bands
    • EMI reduced by an average of 25 dBµV
    • Reduces the external differential-mode input filter size by 50% and lowers systems cost
    • Optimized for CISPR 32 Class B requirements
  • Versatile synchronous buck DC/DC controller
    • Wide input voltage range of 3.5 V to 80 V
    • 1% accurate, fixed 3.3 V, 5 V, 12 V, or adjustable output from 0.8 V to 55 V
    • 150°C maximum junction temperature
    • Shutdown mode current: 2.3 µA
    • No-load sleep current: 9.5 µA
    • Stackable up to two phases
    • Advanced dropout with frequency foldback
  • Switching frequency from 100 kHz to 2.2 MHz
    • SYNC in and SYNC out capability
  • Inherent protection features for robust design
    • Internal hiccup-mode overcurrent protection
    • ENABLE and PGOOD functions
    • VCC, VDDA, and gate-drive UVLO protection
    • Internal or external loop compensation
    • Thermal shutdown protection with hysteresis
  • Create a custom design using the LM5149 with WEBENCH® Power Designer