SNOSDA7D September   2020  – March 2022 LMG3422R030 , LMG3425R030

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Switching Characteristics
    7. 7.7 Typical Characteristics
  8. Parameter Measurement Information
    1. 8.1 Switching Parameters
      1. 8.1.1 Turn-On Times
      2. 8.1.2 Turn-Off Times
      3. 8.1.3 Drain-Source Turn-On Slew Rate
      4. 8.1.4 Turn-On and Turn-Off Switching Energy
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  GaN FET Operation Definitions
      2. 9.3.2  Direct-Drive GaN Architecture
      3. 9.3.3  Drain-Source Voltage Capability
      4. 9.3.4  Internal Buck-Boost DC-DC Converter
      5. 9.3.5  VDD Bias Supply
      6. 9.3.6  Auxiliary LDO
      7. 9.3.7  Fault Detection
        1. 9.3.7.1 Overcurrent Protection and Short-Circuit Protection
        2. 9.3.7.2 Overtemperature Shutdown
        3. 9.3.7.3 UVLO Protection
        4. 9.3.7.4 Fault Reporting
      8. 9.3.8  Drive Strength Adjustment
      9. 9.3.9  Temperature-Sensing Output
      10. 9.3.10 Ideal-Diode Mode Operation
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Slew Rate Selection
          1. 10.2.2.1.1 Start-Up and Slew Rate With Bootstrap High-Side Supply
        2. 10.2.2.2 Signal Level-Shifting
        3. 10.2.2.3 Buck-Boost Converter Design
      3. 10.2.3 Application Curves
    3. 10.3 Do's and Don'ts
  11. 11Power Supply Recommendations
    1. 11.1 Using an Isolated Power Supply
    2. 11.2 Using a Bootstrap Diode
      1. 11.2.1 Diode Selection
      2. 11.2.2 Managing the Bootstrap Voltage
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 Solder-Joint Reliability
      2. 12.1.2 Power-Loop Inductance
      3. 12.1.3 Signal-Ground Connection
      4. 12.1.4 Bypass Capacitors
      5. 12.1.5 Switch-Node Capacitance
      6. 12.1.6 Signal Integrity
      7. 12.1.7 High-Voltage Spacing
      8. 12.1.8 Thermal Recommendations
    2. 12.2 Layout Examples
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Export Control Notice
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

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

Internal Buck-Boost DC-DC Converter

An internal inverting buck-boost converter generates a regulated negative rail for the turn-off supply of the GaN device. The buck-boost converter is controlled by a peak current mode, hysteretic controller. In normal operation, the converter remains in discontinuous-conduction mode, but can enter continuous-conduction mode during start-up and overload the conditions. The converter is controlled internally and requires only a single surface-mount inductor and output bypass capacitor.

The LMG342xR030 supports the GaN operation up to 2.2 MHz. As power consumption is very different in a wide switching frequency range enabled by the GaN device, two peak current limits are used to control the buck-boost converter. The two ranges are separated by IN positive-going threshold frequency. When switching frequency is in the lower range, the peak current is set to the lower value (around 0.4 A) so a smaller inductor can be selected. When switching frequency is in the higher range, the peak current is raised to the higher value (around 1 A) and requires a larger inductor. There is a filter on this frequency detection logic, therefore the LMG342xR030 requires five consecutive cycles at the higher frequency before it is set to the higher buck-boost peak current limit. The current limit does not go down again until power off after the higher limit is set. Even if the switching frequency returns to the lower range, the current limit does not decrease to the lower limit.