Thermal Management
Heat Sink Thermal Resistance Calculator
This calculator determines the maximum allowable thermal resistance of a heat sink based on power dissipation and ambient temperature to prevent component overheating.
Input Parameters
W
°C
°C
°C/W
Calculation Results
Max Heat Sink Resistance (Rthsa) (°C/W)
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Formula & Theory
R_{\theta SA} = \frac{T_{j} - T_{a}}{P_{d}} - R_{\theta JC} - R_{\theta CS}
Frequently Asked Questions
Q: Why is Rthcs included in thermal calculations?
Rthcs (Case-to-Sink thermal resistance) accounts for the thermal interface material (TIM) or grease between the component and the heat sink, which is critical for accurate calculations.
Q: What happens if the calculated thermal resistance is negative?
A negative result indicates that the power dissipation is too high for the component to operate safely at the given ambient temperature, even without a heat sink.