SLUS710E May   2006  – January 2024 TPS28225

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 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Undervoltage Lockout (UVLO)
      2. 6.3.2 Output Active Low
      3. 6.3.3 Enable/Power Good
      4. 6.3.4 3-State Input
        1. 6.3.4.1 TPS28225 3-State Exit Mode
        2. 6.3.4.2 External Resistor Interference
      5. 6.3.5 Bootstrap Diode
      6. 6.3.6 Upper and Lower Gate Drivers
      7. 6.3.7 Dead-Time Control
      8. 6.3.8 Thermal Shutdown
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Four Phases Driven by TPS28225 Driver
        2. 7.2.2.2 Switching The MOSFETs
        3. 7.2.2.3 List of Materials
      3. 7.2.3 Application Curves
    3. 7.3 System Examples
  9. 8 Power Supply Recommendations
  10. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.2.2 Detailed Design Procedure

The bootstrap current can be limited by changing R32 to prevent overcharging of the bootstrap capacitor and to slow the turn-on transition of the high-side MOSFET. This reduces the peak amplitude and ringing of the switching node. Furthermore it minimizes the possibility of Cdv/dt-induced shoot-through of the low-side MOSFETs. The snubbers composed of C50 with R51 and C51 with R52 help to reduce switching noise.

The output component selection considers the requirement of a fast transient response. For output capacitors small capacitance values are chosen because of rapid changes of the output voltage. These changes also require an inductor with low inductance. Due to the small duty cycle the low-side MOSFETs conduct a long time. Two low-side MOSFETs are selected to increase both thermal performance and efficiency.