GE864-QUAD V2 Hardware User Guide
1vv0300841 Rev.5
–
2017-05-11
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Page 33 of 77
6.3.2.
Thermal Design Guidelines
The thermal design for the power supply heat sink must be done
with the following specifications:
Average current consumption during transmission @PWR
level max: 500mA
Average current consumption during transmission @ PWR
level min: 100mA
Average current during Power Saving (CFUN=5): from 1.5 to
3.9mA
Average current during idle (Power Saving disabled): 16mA
NOTE:
The average consumption during transmissions depends on the
power level at which the device is requested to transmit by
the network. The average current consumption hence varies
significantly.
Considering the very low current during idle, especially if
Power Saving function is enabled, it is possible to consider
from the thermal point of view that the device absorbs current
significantly only during calls.
If we assume that the device stays into transmission for short
periods of time (let us say few minutes) and then remains for
a quite long time in idle (let us say one hour), then the
power supply has always the time to cool down between the
calls, and the heat sink could be smaller than the calculated
one for 500mA maximum RMS current, or even could be the simple
chip package (no heat sink).
Moreover, in the average network conditions, the device is
requested to transmit at a lower power level than the maximum,
hence the current consumption will be less than 500mA, usually
around 150mA.
For these reasons the thermal design is rarely a concern and
the simple ground plane where the power supply chip is placed
grants a good thermal condition to avoid overheating as well.
As far as the heat generated by the GE864-QUAD V2 , you can
consider it to be during transmissions of 1W max during
CSD/VOICE calls and 2W max during class10 GPRS upload.
