SLUSFB7A September   2023  – June 2024 LMG3624

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 GaN Power FET Switching Parameters
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 GaN Power FET Switching Capability
      2. 7.3.2 Turn-On Slew-Rate Control
      3. 7.3.3 Current-Sense Emulation
      4. 7.3.4 Input Control Pins (EN, IN)
      5. 7.3.5 AUX Supply Pin
        1. 7.3.5.1 AUX Power-On Reset
        2. 7.3.5.2 AUX Under-Voltage Lockout (UVLO)
      6. 7.3.6 Overcurrent Protection
      7. 7.3.7 Overtemperature Protection
      8. 7.3.8 Fault Reporting
    4. 7.4 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 Turn-On Slew-Rate Design
        2. 8.2.2.2 Current-Sense Design
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Solder-Joint Stress Relief
        2. 8.4.1.2 Signal-Ground Connection
        3. 8.4.1.3 CS Pin Signal
      2. 8.4.2 Layout Example
  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 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • REQ|38
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.1 Overview

The LMG3624 is an integrated 650V 170mΩ GaN power FET intended for use in switching-power converters. The LMG3624 combines the GaN FET, gate driver, current-sense emulation function, and protection features in a 8mm by 5.3mm QFN package.

The 650V rated GaN FET supports the high voltages encountered in off-line power switching applications. The GaN FET low output-capacitive charge reduces both the time and energy needed for power converter switching and is the key characteristic needed to create small, efficient power converters.

The LMG3624 internal gate driver regulates the drive voltage for optimum GaN FET on-resistance. The internal driver reduces total gate inductance and GaN FET common-source inductance for improved switching performance, including common-mode transient immunity (CMTI). The GaN FET turn-on slew rate can be individually programmed to one of four discrete settings for design flexibility with respect to power loss, switching-induced ringing, and EMI.

Current-sense emulation places a scaled replica of the GaN FET drain current on the output of the CS pin. The CS pin is terminated with a resistor to AGND to create the current-sense input signal to the external power supply controller. This CS pin resistor replaces the traditional current-sense resistor, placed in series with the GaN FET source, at significant power and space savings. Furthermore, with no current-sense resistor in series with the GaN FET source, the GaN FET thermal pad can be connected directly to the PCB power ground. This thermal pad connection both improves system thermal performance and provides additional device routing flexibility since full device current can be conducted through the thermal pad.

The AUX input supply wide voltage range is compatible with the corresponding wide range supply rail created by power supply controllers. Low AUX quiescent currents support converter burst-mode operation critical for meeting government light-load efficiency mandates. Further AUX quiescent current reduction is obtained by placing the device in standby mode with the EN pin.

The IN and EN control pins have high input impedance, low input threshold voltage and maximum input voltage equal to the AUX voltage. This allows the pins to support both low voltage and high voltage input signals and be driven with low-power outputs.

The LMG3624 protection features are under-voltage lockout (UVLO), cycle-by-cycle current limit, and overtemperature protection. The overtemperature protection is reported on the open drain FLT output.