SDAA165 January   2026 TPS61287

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Key Parameters for Power MOSFET Selection
    1. 2.1 Static Characteristics
    2. 2.2 Dynamic Characteristics
    3. 2.3 Thermal Parameters
  6. 3Introduction to the MOSFET Selection Tool
    1. 3.1 Input MOSFET Parameters to Calculation Tool
    2. 3.2 Review the Results
  7. 4Calculator Tool MOSFET Selection Example and Bench Evaluation
  8. 5Summary
  9. 6References

2.3 Thermal Parameters

Thermal management verifies the switch operates within the safe operating area (SOA).

  • Junction-to-Ambient Thermal Resistance (RθJA): This defines the temperature rise from the junction to the ambient air for a given power dissipation. A lower RθJA (achieved through better packages or heatsinking) is critical for heat dissipation.
  • Total Power Dissipation (PD): The sum of conduction and switching losses. The junction temperature can be calculated as: TJ = TA + (PD × RθJA), where TA is the ambient temperature. TJ must always remain below the maximum rating (typically 150°C or 175°C).