MOSFET Power Loss & Junction Temperature Calculator

This calculator helps you determine if your MOSFET and cooling solution can safely manage both conduction and switching heat without exceeding safe operating limits.

Use this tool to:

  1. Calculate real-time power dissipation, accounting for both RDS(on) and switching frequency losses.
  2. Select the correct package or heatsink (e.g., DPAK vs. TO-220 with finned cooling) for your specific current load.
  3. Identify thermal bottlenecks and decide when a lower RDS(on) device or improved thermal management is necessary to prevent failure.
Input Parameters
Results
Thermal Warning: Junction temperature exceeds 125°C. Additional cooling or lower RDS(on) required.

*Calculation assumes linear switching transitions and steady-state thermal equilibrium.

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