SNOSD81B September   2018  – January 2020

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Block Diagram
      2.      Switching Performance at >100 V/ns
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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. 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
  8. 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 Start Up Sequence
      5. 8.3.5 R-C Decoupling for IN pin
      6. 8.3.6 Low Power Mode
      7. 8.3.7 Fault Detection
        1. 8.3.7.1 Over-current Protection
        2. 8.3.7.2 Over-Temperature Protection and UVLO
      8. 8.3.8 Drive Strength Adjustment
    4. 8.4 Safe Operation Area (SOA)
      1. 8.4.1 Repetitive SOA
  9. 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. 9.3 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

11.1.5 Signal Integrity

The control signals to the LMG341xR050 must be protected from the high dv/dt that the GaN power stage produces. Coupling between the control signals and the drain may cause circuit instability and potential destruction. Route the control signals (IN, FAULT and LPM) over a ground plane located on an adjacent layer. For example, in the layout in Figure 24, all the signals are routed on the top layer directly over the signal GND plane on the first inner copper layer.

The signals for the high-side device are often particularly vulnerable. Coupling between these signals and system ground planes could cause issues in the circuit. Keep the traces associated with the control signals away from drain copper. Shielding traces adjacent to the signal traces can be useful to minimize parasitic coupling. For the high-side level shifter, ensure no copper from either the input or output side extends beneath the isolator or the device's CMTI may be compromised.