Related Resources: heat transfer

Selecting Heat Sink Transistor Equation and Calculator

Heat Transfer Engineering
Thermodynamics
Engineering Physics

Selecting a Heat Sink for a Transistor Equation and Calculator:

Assumptions:

1 Steady operating conditions exist.
2 The transistor case is isothermal at 90°C.
3 The contact resistance between the transistor and the heat sink is negligible.

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Preview: Selecting a Heat Sink for a Transistor Calculator

 

A commercially available heat sink is to be selected to keep the case temperature of a transistor below design temperature.

Rate of heat transfer

rate of heat transfer

Where:

Q = Heat Steady State Transfer (W)
R = Thermal Resistance of Heat Sink (°C/W)
ΔT = Tcase - Tambient (°C)

See Natural Convection Radiation Thermal Resistance of Heat Sinks