SNOSD97D October   2020  – February 2024 LMG3522R030-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 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. 6 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
  8. 7 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 Detection
        1. 7.3.7.1 Overcurrent Protection and Short-Circuit Protection
        2. 7.3.7.2 Overtemperature Shutdown
        3. 7.3.7.3 UVLO Protection
        4. 7.3.7.4 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 Overtemperature-Shutdown Ideal-Diode Mode
    4. 7.4 Start-Up Sequence
    5. 7.5 Safe Operation Area (SOA)
      1. 7.5.1 Repetitive SOA
    6. 7.6 Device Functional Modes
  9. 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 Slew Rate Selection
          1. 8.2.2.1.1 Start-Up and Slew Rate With Bootstrap High-Side Supply
        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. 9 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

7.3.8 Drive-Strength Adjustment

The LMG3522R030-Q1 allows users to adjust the drive strength of the device and obtain a desired slew rate, which provides flexibility when optimizing switching losses and noise coupling.

To adjust drive strength, a resistor can be placed between the RDRV pin and SOURCE pin. The resistance determines the slew rate of the device, from 20 V/ns to 150 V/ns, during turn-on. On the other hand, there are two dv/dt values that can be selected without the resistor: shorting the RDRV pin to ground sets the slew rate to 150 V/ns, and shorting the RDRV pin to LDO5V sets the slew rate to 100 V/ns. The device detects the short to LDO5V one time at power up. Once the short to LDO5V condition is detected, the device no longer monitors the RDRV pin. Otherwise, the RDRV pin is continuously monitored and the dv/dt setting can be changed by modulating the resistance during device operation. The modulation must be fairly slow since there is significant internal filtering to reject switching noise.

Note: Parasitic power loop inductance can influence the voltage slew rate reading from the VDS switching waveform. The inductance induces a drop on VDS in the current rising phase before voltage falling phase, if this drop is more than 20% of the VDC, the voltage slew rate reading can be influenced. Refer to Section 8.5.1.2 for the power loop design guideline and how to estimate the parasitic power loop inductance.