SNOSCY4E March   2015  – October 2018 LMG5200

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Block Diagram
  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 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Propagation Delay and Mismatch Measurement
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Control Inputs
      2. 8.3.2 Start-up and UVLO
      3. 8.3.3 Bootstrap Supply Voltage Clamping
      4. 8.3.4 Level Shift
    4. 8.4 Device Functional Modes
  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 VCC Bypass Capacitor
        2. 9.2.2.2 Bootstrap Capacitor
        3. 9.2.2.3 Power Dissipation
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Examples
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
    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
    1. 13.1 Package Information

9.2.2.2 Bootstrap Capacitor

The bootstrap capacitor provides the gate charge for the high-side gate drive, dc bias power for HB UVLO circuit, and the reverse recovery charge of the bootstrap diode. The required bypass capacitance can be calculated using Equation 2.

Equation 2. CBST = (QgH + Qrr + IHB * tON(max)) / ΔV

where

  • IHB is the quiescent current of the high-side gate driver (150 µA, maximum)
  • tON(maximum) is the maximum on-time period of the high-side gate driver
  • Qrr is the reverse recovery charge of the bootstrap diode
  • QgH is the gate charge of the high-side GaN FET
  • ΔV is the permissible ripple in the bootstrap capacitor (< 100 mV, typical)

A 0.1-µF, 16-V, 0402 ceramic capacitor is suitable for most applications. Place the bootstrap capacitor as close as possible to the HB and HS pins.