SNVSCB0C January   2023  – September 2023 LM2105

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Revision History
  6. Pin Configuration and Functions
  7. 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 Timing Diagrams
    8. 6.8 Typical Characteristics
  8. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Start-Up and UVLO
      2. 7.3.2 Input Stages
      3. 7.3.3 Level Shift
      4. 7.3.4 Output Stages
      5. 7.3.5 SH Transient Voltages Below Ground
    4. 7.4 Device Functional Modes
  9. 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 Select Bootstrap and GVDD Capacitor
        2. 8.2.2.2 Select External Gate Driver Resistor
        3. 8.2.2.3 Estimate the Driver Power Loss
      3. 8.2.3 Application Curves
  10. Power Supply Recommendations
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

Layout Guidelines

Optimum performance of half-bridge gate drivers cannot be achieved without taking due considerations during circuit board layout. The following points are emphasized:

  1. Low-ESR and low-ESL capacitors must be connected close to the IC between GVDD and GND pins and between BST and SH pins to support high peak currents being drawn from GVDD and BST during the turn-on of the external MOSFETs.
  2. To prevent large voltage transients at the drain of the top MOSFET, a low-ESR electrolytic capacitor and a good-quality ceramic capacitor must be connected between the MOSFET drain and ground (GND).
  3. To avoid large negative transients on the switch node (SH) pin, the parasitic inductances between the source of the top MOSFET and the drain of the bottom MOSFET (synchronous rectifier) must be minimized.
  4. Grounding considerations:
    • The first priority in designing grounding connections is to confine the high peak currents that charge and discharge the MOSFET gates to a minimal physical area. This will decrease the loop inductance and minimize noise issues on the gate terminals of the MOSFETs. The gate driver must be placed as close as possible to the MOSFETs.
    • The second consideration is the high current path that includes the bootstrap capacitor, the bootstrap diode, the local ground referenced bypass capacitor, and the low-side MOSFET body diode. The bootstrap capacitor is recharged on a cycle-by-cycle basis through the bootstrap diode from the ground referenced GVDD bypass capacitor. The recharging occurs in a short time interval and involves high peak current. Minimizing this loop length and area on the circuit board is important to ensure reliable operation.