SNOSD74B May   2019  – January 2020 LMG1025-Q1

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Typical (Simplified) System Diagram
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  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 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Input Stage
      2. 7.3.2 Output Stage
      3. 7.3.3 Bias Supply and Under Voltage Lockout
      4. 7.3.4 Overtemperature Protection (OTP)
    4. 7.4 Device Functional Modes
  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 Handling Ground Bounce
        2. 8.2.2.2 Creating Nanosecond Pulse
      3. 8.2.3 VDD and Overshoot
      4. 8.2.4 Operating at Higher Frequency
      5. 8.2.5 Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Gate Drive Loop Inductance and Ground Connection
      2. 10.1.2 Bypass Capacitor
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Gate Drive Loop Inductance and Ground Connection

A compact, low-inductance gate-drive loop is essential to achieving fast switching frequencies with the LMG1025-Q1. The LMG1025-Q1 should be placed as close to the GaN FET as possible, with gate drive resistors immediately connecting OUTH and OUTL to the FET gate. Large traces need to be used to minimize resistance and parasitic inductance.

To minimize gate drive loop inductance, the source return should be on layer 2 of the PCB, immediately under the component (top) layer. Vias immediately adjacent to both the FET source and the LMG1025-Q1 GND pin connect to this plane with minimal impedance. Finally, care must be taken to connect the GND plane to the source power plane only at the FET to minimize common-source inductance and to reduce coupling to the ground plane.