GE866-QUAD Hardware User Guide
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Page 33 of 82
Mod. 0805 2011-07 Rev.2
The three cells Ni/Cd or Ni/MH 3.6 V Nom. battery types or 4V PB types MUST NOT
BE USED DIRECTLY since their maximum voltage can rise over the absolute
maximum voltage for the GE866-QUAD and damage it.
NOTE:
DON'T USE any Ni-Cd, Ni-MH, and Pb battery types directly connected with GE866-
QUAD. Their use can lead to overvoltage on the GE866-QUAD and damage it. USE
ONLY Li-Ion battery types.
•
A Bypass low ESR capacitor of adequate capacity must be provided in order to
cut the current absorption peaks, a 100
μ
F tantalum capacitor is usually suited.
•
Make sure the low ESR capacitor (usually a tantalum one) is rated at least 10V.
•
A protection diode should be inserted close to the power input, in order to save
the GE866-QUAD from power polarity inversion. Otherwise the battery connector
should be done in a way to avoid polarity inversions when connecting the battery.
•
The battery capacity must be at least 500mAh in order to withstand the current
peaks of 2A; the suggested capacity is from 500mAh to 1000mAh.
6.3.2.
Thermal Design Guidelines
The thermal design for the power supply heat sink should be done with the following
specifications:
See Par. 6.2 Power Consumption
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.
For the heat generated by the GE866-QUAD, you can consider it to be during
transmission 1W max during CSD/VOICE calls and 2W max during class10 GPRS
upload.
