Hardware Documentation armStone
™A9
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5.3
Power consumption and cooling
Depend you product version you will have different temperature range and power
consumption of the module.
The operating temperature can be measured on the mounting holes or the golden cooling
plate on top of the module and
shouldn’t exceed the maximum operating temperature of
the board
(85°C for the most of our armStoneA9 boards).
The maximum power consumption of the board could be 11.5 Watt. This value is with 100%
working of 4 cores and full working 3D engines. Calculating with this scenario does need an
expensive cooling.
Depend your application and your worst case scenario the maximum power consumption is
much lower. This will save money on your cooling solution. We recommend to measure this
with your application. We see values between max. 4 and 7 Watt on different custom
applications.
Because the different environments for air temperature, airflow, thermal radiation, power
consumption of the board on your application and the power consumption of other
components like power supply and LCD inside the system you have to calculate a working
cooling solution for the board. Just cooling the CPU with 70-90% of the power consumption
of the entire board is the best way to cool the board.
To calculate your cooling we recommend this helpful literature
fischerelektronik.de/web_fisch…eKataloge/Heatsinks/#/18/
http://www.eetimes.com/document.asp?doc_id=1276748
http://www.eetimes.com/document.asp?doc_id=1276750
