SNOSDA8C October   2020  – February 2024 LMG3422R050 , LMG3426R050

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
      4. 6.1.4 Turn-On and Turn-Off Switching Energy
      5. 6.1.5 Zero-Voltage Detection Times
    2. 6.2 Safe Operation Area (SOA)
      1. 6.2.1 Repetitive SOA
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
      1. 7.2.1 LMG3422R050 Functional Block Diagram
      2. 7.2.2 LMG3426R050 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 Overtemperature-Shutdown Ideal-Diode Mode
      11. 7.3.11 Zero-Voltage Detection (ZVD)
    4. 7.4 Start-Up Sequence
    5. 7.5 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
        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

Package Options

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

7.3.8 Drive-Strength Adjustment

The LMG342xR050 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 GND pin. The resistance determines the slew rate of the device, from 20 V/ns to 150V/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 150V/ns, and shorting the RDRV pin to LDO5V sets the slew rate to 100V/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.