SLUSF82B January   2024  – November 2024 LMG3100R017 , LMG3100R044

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 Thermal Information
    6. 5.6 Electrical Characteristics
    7. 5.7 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Propagation Delay and Mismatch Measurement
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Control Inputs
      2. 7.3.2 Start-up and UVLO
      3. 7.3.3 Bootstrap Supply Voltage Clamping
      4. 7.3.4 Level Shift
    4. 7.4 Device Functional Modes
  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 VCC Bypass Capacitor
        2. 8.2.2.2 Bootstrap Capacitor
        3. 8.2.2.3 Slew Rate Control
        4. 8.2.2.4 Use With Analog Controllers
        5. 8.2.2.5 Power Dissipation
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Examples
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

8.4.1 Layout Guidelines

To maximize the efficiency benefits of fast switching, it is extremely important to optimize the board layout such that the power loop impedance is minimal. When using a multilayer board (more than 2 layers), power loop parasitic impedance is minimized by having the return path to the input capacitor (between VIN and PGND), small and directly underneath the first layer as shown in Figure 8-6 and Figure 8-7. Loop inductance is reduced due to flux cancellation as the return current is directly underneath and flowing in the opposite direction.

Insufficient attention to the above power loop layout guidelines can result in excessive overshoot and undershoot on the switch node.

It is also critical that the VCC capacitors and the bootstrap capacitors are as close as possible to the device and in the first layer. Carefully consider the AGND connection of LMG3100 device. It must NOT be directly connected to PGND so that PGND noise does not directly shift AGND and cause spurious switching events due to noise injected in HI and LI signals.