SLVSH20B October   2023  – May 2024 TPSM86837 , TPSM86838

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  The Adaptive On-Time Control and PWM Operation
      2. 6.3.2  Mode Selection
        1. 6.3.2.1 FCCM Control and Eco-mode Control
      3. 6.3.3  Soft Start and Prebiased Soft Start
      4. 6.3.4  Enable and Adjusting Undervoltage Lockout
      5. 6.3.5  Output Overcurrent Limit and Undervoltage Protection
      6. 6.3.6  Overvoltage Protection
      7. 6.3.7  UVLO Protection
      8. 6.3.8  Thermal Shutdown
      9. 6.3.9  Output Voltage Discharge
      10. 6.3.10 Power Good
      11. 6.3.11 Large Duty Operation
    4. 6.4 Device Functional Modes
      1. 6.4.1 Standby Operation
      2. 6.4.2 Light Load Operation
  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 Output Voltage Resistors Selection
        2. 7.2.2.2 Output Filter Selection
        3. 7.2.2.3 Input Capacitor Selection
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
      1. 7.3.1 Application Thermal Considerations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Third-Party Products Disclaimer
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.1 Application Thermal Considerations

The power module integrates the main power dissipating elements, the power switches and magnetics, all into one package, which enables smaller design size and simplifies the development. Therefore, in addition to the IC losses, the heat generated from the inductor direct current resistance (DCR) and core losses add to the total power dissipated in the package. Under the same operating conditions as the discrete counterparts (which have an external inductor), the module has the challenge of dissipating more heat through a smaller surface area. There is a constraint on the maximum output current that modules can deliver at higher operating ambient temperatures due to limitations in maximum temperature ratings for both the inductor and IC.

The temperature rise of module can be calculated by using efficiency and EVM effective RθJA. Equation 11 calculates the power loss from the data sheet efficiency curves:

Equation 11. Power Loss=(VOUT×IOUT)×( 1η-1 ) 

Where ƞ is the application conditions efficiency. As an example, Figure 7-2 shows the efficiency curve at 25°C for the 24Vin, 1.8Vout, 800kHz condition. At 8A load, with nearly 81% efficiency, Equation 11 calculates the power loss as 3.378W. Multiplying by the EVM effective RθJA 24 °C/W gives a temperature rise of 81°C.

The maximum temperature rating for TPSM8683x is 150°C. Subtracting this temperature rise from the 150°C maximum temperature results in a maximum ambient temperature of 69°C. Consider operation within this ambient temperature.