SNOSD10F April   2016  – May 2020

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Simplified Block Diagram
      2.      Switching Performance at >100 V/ns
  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. Parameter Measurement Information
    1. 7.1 Switching Parameters
      1. 7.1.1 Turn-on Delays
      2. 7.1.2 Turn-off Delays
      3. 7.1.3 Drain Slew Rate
      4. 7.1.4 Turn-on and Turn-off Energy
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Direct-Drive GaN Architecture
      2. 8.3.2 Internal Buck-Boost DC-DC Converter
      3. 8.3.3 Internal Auxiliary LDO
      4. 8.3.4 Fault Detection
        1. 8.3.4.1 Over-current Protection
        2. 8.3.4.2 Over-Temperature Protection and UVLO
      5. 8.3.5 Drive Strength Adjustment
    4. 8.4 Device Functional Modes
      1. 8.4.1 Low-Power Mode
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Slew Rate Selection
          1. 9.2.2.1.1 Startup and Slew Rate with Bootstrap High-Side Supply
        2. 9.2.2.2 Signal Level-Shifting
        3. 9.2.2.3 Buck-Boost Converter Design
      3. 9.2.3 Application Curves
    3. 9.3 Paralleling GaN Devices
    4. 9.4 Do's and Don'ts
  10. 10Power Supply Recommendations
    1. 10.1 Using an Isolated Power Supply
    2. 10.2 Using a Bootstrap Diode
      1. 10.2.1 Diode Selection
      2. 10.2.2 Managing the Bootstrap Voltage
      3. 10.2.3 Reliable Bootstrap Start-up
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Power Loop Inductance
      2. 11.1.2 Signal Ground Connection
      3. 11.1.3 Bypass Capacitors
      4. 11.1.4 Switch-Node Capacitance
      5. 11.1.5 Signal Integrity
      6. 11.1.6 High-Voltage Spacing
      7. 11.1.7 Thermal Recommendations
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Direct-Drive GaN Architecture

The LMG341xR070 utilizes a series FET to ensure the GaN module stays off when VDD is not applied. When this FET is off, the gate of the GaN transistor is held within a volt of the FET's source. As the silicon FET blocks the drain voltage, the VGS of the GaN transistor decreases until it passes its threshold voltage. Then, the GaN transistor turns off and blocks the remaining drain voltage.

When the LMG341xR070 is powered up, the internal buck-boost converter generates a negative voltage (VNEG) that is sufficient to directly turn off the GaN transistor. In this case, the silicon FET is held on and the GaN transistor is gated directly with the negative voltage. During operation, this removes the switching loss of silicon FET.