SNVSAR1B March   2017  – March 2018 LM5113-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Application 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 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Input and Output
      2. 7.3.2 Start-Up and UVLO
      3. 7.3.3 HS Negative Voltage and Bootstrap Supply Voltage Clamping
      4. 7.3.4 Level Shift
    4. 7.4 Device Functional Modes
  8. 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 VDD Bypass Capacitor
        2. 8.2.2.2 Bootstrap Capacitor
        3. 8.2.2.3 Power Dissipation
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

8.2.2.2 Bootstrap Capacitor

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

Equation 2. LM5113-Q1 30162940.gif

where

  • IHB is the quiescent current of the high-side driver.
  • ton is the maximum on-time period of the high-side transistor.

A good-quality, ceramic capacitor must be used for the bootstrap capacitor. TI recommends placement of the bootstrap capacitor as close as possible to the HB and HS pin.