Tools/Heat Sink Calculator

Heat Sink Calculator

Calculate required heatsink thermal resistance and size

Thermal Parameters

TjθjcTcθcsTsθsaTa

From component datasheet

TIM: 0.2-1.0°C/W typical

Heatsink Requirements

Large heatsink required

Required θsa

6.00

°C/W

Est. Surface Area

208.3

cm²

Total θja

8.50

°C/W

Case Temp (Tc)

105.0°C

Sink Temp (Ts)

100.0°C

Est. Size

122mm

square base

Conv. Coeff.

8.0

W/m²K

Common Heatsink θsa Values

Typeθsa (°C/W)Application
TO-220 clip8-15Low power, no fan
Small extruded (25×25mm)5-101-5W natural
Medium extruded (50×50mm)2-55-15W natural
Large extruded (100×100mm)1-215-50W natural
Forced air (50×50mm)0.5-220-50W with fan
Active cooler0.1-0.550-200W
Use thermal interface material (TIM) to reduce θcs. Thermal paste: 0.2-0.5°C/W, thermal pads: 0.5-2°C/W. Mounting pressure significantly affects performance.

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