A54SX08A-FTQG144 Datasheet, PDF (33/108 Pages) Actel Corporation – SX-A Family FPGAs

To determine the heat sink's thermal performance, use the following equation:
θ_JA(TOTAL) = θ_JC + θ_CS + θ_SA
where:
θ_CS =
=
θ_SA =
0.37°C/W
thermal resistance of the interface material between the case and the heat
sink, usually provided by the thermal interface manufacturer
thermal resistance of the heat sink in °C/W
SX-A Family FPGAs
EQ 2-14
θ_SA = θ_JA(TOTAL) – θ_JC – θ_CS
θ_SA = 13.33°C/W – 3.20°C/W – 0.37°C/W
EQ 2-15
θ_SA = 9.76°C/W
A heat sink with a thermal resistance of 9.76°C/W or better should be used. Thermal resistance of heat sinks is a
function of airflow. The heat sink performance can be significantly improved with the presence of airflow.
Carefully estimating thermal resistance is important in the long-term reliability of an Actel FPGA. Design engineers
should always correlate the power consumption of the device with the maximum allowable power dissipation of the
package selected for that device, using the provided thermal resistance data.
Note: The values may vary depending on the application.
v5.3
2-13