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

3 Description

The LM5148-Q1 is a 80V, ultra-low IQ synchronous buck DC/DC controller for high-current, single-output applications. The controller uses a peak current-mode control architecture for easy loop compensation, fast transient response, and excellent load and line regulation. The LM5148-Q1 can be set up in dual-phase mode (paralleled output) with accurate current sharing for high-current applications. The device can operate at input voltages as low as 3.5V, at nearly 100% duty cycle if needed.

The LM5148-Q1 has a unique EMI reduction feature known as Dual Random Spread Spectrum (DRSS). Combining low-frequency triangular and high-frequency random modulations mitigates EMI disturbances across lower and higher frequency bands, respectively. This hybrid technique aligns with the multiple resolution bandwidth (RBW) settings specified in industry-standard EMC tests.

Package Information
PART NUMBER PACKAGE(1) PACKAGE SIZE(2)
LM5148-Q1 RGY (VQFN, 24) 5.50mm × 3.50mm
RGY (VQFN, 19) 4.50mm × 3.50mm
(1) For more information, see Section 11.
(2) The package size (length × width) is a nominal value and includes pins, where applicable.
LM5148-Q1 Typical Application SchematicTypical Application Schematic
LM5148-Q1 CISPR 25 EMI Performance - 150kHz to 30MHzCISPR 25 EMI Performance - 150kHz to 30MHz