SNVSBB3A October   2019  – April 2024 LM5163

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Control Architecture
      2. 6.3.2  Internal VCC Regulator and Bootstrap Capacitor
      3. 6.3.3  Regulation Comparator
      4. 6.3.4  Internal Soft Start
      5. 6.3.5  On-Time Generator
      6. 6.3.6  Current Limit
      7. 6.3.7  N-Channel Buck Switch and Driver
      8. 6.3.8  Synchronous Rectifier
      9. 6.3.9  Enable/Undervoltage Lockout (EN/UVLO)
      10. 6.3.10 Power Good (PGOOD)
      11. 6.3.11 Thermal Protection
    4. 6.4 Device Functional Modes
      1. 6.4.1 Shutdown Mode
      2. 6.4.2 Active Mode
      3. 6.4.3 Sleep Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Custom Design With WEBENCH® Tools
        2. 7.2.2.2 Switching Frequency (RRON)
        3. 7.2.2.3 Buck Inductor (LO)
        4. 7.2.2.4 Output Capacitor (COUT)
        5. 7.2.2.5 Input Capacitor (CIN)
        6. 7.2.2.6 Type-3 Ripple Network
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 Compact PCB Layout for EMI Reduction
        2. 7.4.1.2 Feedback Resistors
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Third-Party Products Disclaimer
      2. 8.1.2 Development Support
        1. 8.1.2.1 Custom Design With WEBENCH® Tools
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

7.4.1.1 Compact PCB Layout for EMI Reduction

Radiated EMI generated by high di/dt components relates to pulsing currents in switching converters. The larger the area covered by the path of a pulsing current, the more electromagnetic emission is generated. The key to minimizing radiated EMI is to identify the pulsing current path and minimize the area of that path.

Figure 7-18 denotes the critical switching loop of the buck converter power stage in terms of EMI. The topological architecture of a buck converter means that a particularly high di/dt current path exists in the loop comprising the input capacitor and the integrated MOSFETs of the LM5163, and it becomes mandatory to reduce the parasitic inductance of this loop by minimizing the effective loop area.

GUID-760F44EF-3294-4846-8040-A83C09C568E5-low.gifFigure 7-18 DC/DC Buck Converter With Power Stage Circuit Switching Loop

The input capacitor provides the primary path for the high di/dt components of the current of the high-side MOSFET. Placing a ceramic capacitor as close as possible to the VIN and GND pins is the key to EMI reduction. Keep the trace connecting SW to the inductor as short as possible and just wide enough to carry the load current without excessive heating. Use short, thick traces or copper pours (shapes) for current conduction path to minimize parasitic resistance. Place the output capacitor close to the VOUT side of the inductor, and connect the return terminal of the capacitor to the GND pin and exposed PAD of the LM5163.