SLVSHB5A October   2024  – November 2024 TPS61287

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 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 Enable and Start-up
      2. 6.3.2 Undervoltage Lockout (UVLO)
      3. 6.3.3 Programmable EN/UVLO
      4. 6.3.4 Switching Valley Current Limit
      5. 6.3.5 External Clock Synchronization
      6. 6.3.6 Stackable Multi-phase Operation
      7. 6.3.7 Device Functional Modes
        1. 6.3.7.1 Forced PWM Mode
        2. 6.3.7.2 Auto PFM Mode
      8. 6.3.8 Overvoltage Protection
      9. 6.3.9 Thermal Shutdown
  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 Setting Output Voltage
        2. 7.2.2.2 Inductor Selection
        3. 7.2.2.3 Bootstrap And VCC Capacitors Selection
        4. 7.2.2.4 MOSFET Selection
        5. 7.2.2.5 Input Capacitor Selection
        6. 7.2.2.6 Output Capacitor Selection
        7. 7.2.2.7 Loop Stability
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
        1. 7.4.2.1 Thermal Considerations
  9. 8 Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.4.2.1 Thermal Considerations

The maximum IC junction temperature should be restricted to 125°C under normal operating conditions. Calculate the maximum allowable dissipation, PD(max), and keep the actual power dissipation less than or equal to PD(max). The maximum-power-dissipation limit is determined using:

Equation 19. TPS61287

where

  • TA is the maximum ambient temperature for the application.
  • RθJA is the junction-to-ambient thermal resistance given in the Section 5.4 table.

The TPS61287 comes in a thermally-enhanced VQFN package. The real junction-to-ambient thermal resistance of the package greatly depends on the PCB type, layout, and thermal pad connection. Using thick PCB copper and soldering the thermal pad to a large ground plate enhance the thermal performance. Using more vias connects the ground plate on the top layer and bottom layer around the IC without solder mask also improves the thermal capability.