PC7410 datasheet(16/54 Pages) ATMEL

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PC7410

2141D–HIREL–02/04

Figure 7. Thermalloy #2328B Heat Sink-to-ambient Thermal Resistance vs. Airflow

Velocity

Assuming an air velocity of 0.5 m/s, the effective R

sa is 7°C/W, thus

resulting in a die-junction temperature of approximately 75

°C which is well within the

maximum operating temperature of the component.

Other heat sinks offered by Chip Coolers, IERC, Thermalloy, Wakefield Engineering and

Aavid Engineering offer different heat sink-to-ambient thermal resistances and may or

may not need air flow.

Though the die junction-to-ambient and the heat sink-to-ambient thermal resistances

are a common figure of merit used for comparing the thermal performance of various

microelectronic packaging technologies, one should exercise caution when only using

this metric in determining thermal management because no single parameter can ade-

quately describe three-dimensional heat flow. The final die-junction operating

temperature is not only a function of the component-level thermal resistance, but of the

system-level design and its operating conditions. In addition to the component's power

consumption, a number of factors affect the final operating die-junction temperature –

airflow, board population (local heat flux of adjacent components), heat sink efficiency,

heat sink attach, heat sink placement, next-level interconnect technology, system air

temperature rise, altitude, etc.

00.5

11.5

22.5

3.5

Thermalloy #2328B Pin-Fin Heat Sink

(25 x 28 x 15 mm)

Approach Air Velocity (m/s)

°C 5°C

0,03

°CW

⁄

1,0

°CW

⁄

°CW

⁄

() 5W

PC7410 Datasheet(PDF) 16 Page - ATMEL Corporation