579302B00000G Aavid Thermalloy, 579302B00000G Datasheet - Page 9

• Manufacturer Part Number: 579302B00000G
• Description: HEATSINK TO-220 SNAP-DOWN .75"
• Manufacturer: Aavid Thermalloy

Specifications of 579302B00000G

• Package Cooled: TO-220
• Attachment Method: Clip
• Outline: 24.89mm x 19.05mm
• Height: 0.440" (11.18mm)
• Power Dissipation @ Temperature Rise: 3W @ 50°C
• Thermal Resistance @ Forced Air Flow: 6°C/W @ 500 LFM
• Thermal Resistance @ Natural: 16.8°C/W
• Product: Heatsinks
• Fin Style: Two Side Fins
• Thermal Resistance: 16.8 C / W
• Dimensions: 19.05 mm L x 24.89 mm W x 11.18 mm H
• Designed For: TO-220
• Color: Black
• Packages Cooled: TO-220
• External Width - Metric: 24.89mm
• External Height - Metric: 11.18mm
• External Length - Metric: 19.05mm
• Width: 24.89mm
• Length: 19.05mm
• Rohs Compliant: Yes
• External Width - Imperial: 0.98"
• External Height - Imperial: 0.44"
• External Length - Imperial: 0.75"
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 002636; 579302B00000; HS220

The basic equation for heat transfer or power dissipation may be stated as follows:
Where:
P D = the power dissipated by the semiconductor device in watts.
ΔT = the temperature difference of driving potential which causes the flow of heat.
ΣR θ = the sum of the thermal resistances of the heat flow path across which ΔT exists.
The above relationship may be stated in the following forms:
The above equations are generally used to determine the required thermal resistance of the heat sink (R θSA ),
since the heat dissipation, maximum junction and/or case temperature, and ambient temperature are known or set.
Figure 1 indicates the location of the various heat
flow paths, temperatures and thermal resistances.
FIGURE 1
Where:
T J = the junction temperature in °C (maximum is usually stated by the manufacturer of the semiconductor device).
T C = case temperature of the semiconductor device in °C.
T S = temperature of the heat sink mounting surface in thermal contact with the semiconductor device in °C.
T A = ambient air temperature in °C.
How to select a heat sink
P D =
R θJC = thermal resistance from junction to case of the semiconductor device in °C per watt
R θCS = thermal resistance through the interface between the semiconductor device
R θSA = thermal resistance from mounting surface to ambient or thermal resistance of heat sink in °C per watt.
P D =
Semiconductor case
www.aavidthermalloy.com
R θJC + R θCS + R θSA
(cooler/dissipator)
Mounting surface
(usually stated by manufacturer of semiconductor device).
(heat source)
and the surface on which it is mounted in °C per watt.
Δ T
ΣR θ
Junction
Interface
T J –T A
P
R
D
θJC
R
θCS
T
J
T
C
T
S
surface to ambient, equation (3)
AMERICA
to ambient, equation (1)
Heat flow path junction
to ambient equation (2)
EUROPE
Heat flow path mounting
Heat flow path case
R
θSA
Italy Tel: [phone] email: [e-mail]
United Kingdom Tel: [phone] email: [e-mail]
USA Tel: [phone] email: [e-mail]
P D =
P
D
Atmosphere
R θCS + R θSA
or ambient
T
T
T C –T A
A
A
The common practice is to represent the system with
a network of resistances in series as shown in Figure 2.
FIGURE 2
T J
R θJC
ASIA
P D =
How To Select a Heat Sink
Singapore Tel: [phone] email: [e-mail]
Taiwan Tel: [phone] email: [e-mail]
T S –T A
T C
R θSA
R θCS
T S
R θSA
T A
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