SNOSDI2 March   2024 LMG3425R050

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Pin Configuration and Functions
  6. 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 Switching Characteristics
    7. 5.7 Typical Characteristics
  7. Parameter Measurement Information
    1. 6.1 Switching Parameters
      1. 6.1.1 Turn-On Times
      2. 6.1.2 Turn-Off Times
      3. 6.1.3 Drain-Source Turn-On Slew Rate
      4. 6.1.4 Turn-On and Turn-Off Switching Energy
    2. 6.2 Safe Operation Area (SOA)
      1. 6.2.1 Repetitive SOA
  8. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  GaN FET Operation Definitions
      2. 7.3.2  Direct-Drive GaN Architecture
      3. 7.3.3  Drain-Source Voltage Capability
      4. 7.3.4  Internal Buck-Boost DC-DC Converter
      5. 7.3.5  VDD Bias Supply
      6. 7.3.6  Auxiliary LDO
      7. 7.3.7  Fault Protection
        1. 7.3.7.1 Overcurrent Protection and Short-Circuit Protection
        2. 7.3.7.2 Overtemperature Shutdown Protection
        3. 7.3.7.3 UVLO Protection
        4. 7.3.7.4 High-Impedance RDRV Pin Protection
        5. 7.3.7.5 Fault Reporting
      8. 7.3.8  Drive-Strength Adjustment
      9. 7.3.9  Temperature-Sensing Output
      10. 7.3.10 Ideal-Diode Mode Operation
        1. 7.3.10.1 Operational Ideal-Diode Mode
        2. 7.3.10.2 Overtemperature-Shutdown Ideal-Diode Mode
    4. 7.4 Start-Up Sequence
    5. 7.5 Device Functional Modes
  9. 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 Slew Rate Selection
        2. 8.2.2.2 Signal Level-Shifting
        3. 8.2.2.3 Buck-Boost Converter Design
      3. 8.2.3 Application Curves
    3. 8.3 Do's and Don'ts
    4. 8.4 Power Supply Recommendations
      1. 8.4.1 Using an Isolated Power Supply
      2. 8.4.2 Using a Bootstrap Diode
        1. 8.4.2.1 Diode Selection
        2. 8.4.2.2 Managing the Bootstrap Voltage
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
        1. 8.5.1.1 Solder-Joint Reliability
        2. 8.5.1.2 Power-Loop Inductance
        3. 8.5.1.3 Signal-Ground Connection
        4. 8.5.1.4 Bypass Capacitors
        5. 8.5.1.5 Switch-Node Capacitance
        6. 8.5.1.6 Signal Integrity
        7. 8.5.1.7 High-Voltage Spacing
        8. 8.5.1.8 Thermal Recommendations
      2. 8.5.2 Layout Examples
  10. 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 Export Control Notice
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
  • RQZ|54
Thermal pad, mechanical data (Package|Pins)
Orderable Information

Switch-Node Capacitance

GaN devices have very low output capacitance and switch quickly with a high dv/dt, yielding very low switching losses. To preserve this low switching losses, additional capacitance added to the output node must be minimized. The PCB capacitance at the switch node can be minimized by following these guidelines:

  • Minimize overlap between the switch-node plane and other power and ground planes.
  • Make the GND return path under the high-side device thinner while still maintaining a low-inductance path.
  • Choose high-side isolator ICs and bootstrap diodes with low capacitance.
  • Place the power inductor as close to the GaN device as possible.
  • Power inductors must be constructed with a single-layer winding to minimize intra-winding capacitance.
  • If a single-layer inductor is not possible, consider placing a small inductor between the primary inductor and the GaN device to effectively shield the GaN device from the additional capacitance.
  • If a back-side heat-sink is used, use the least amount of area of the switch-node copper coverage on the bottom copper layer to improve the thermal dissipation.