User's Manual

GE866-DUAL Hardware User Guide
1VV0301051 Rev. 2 – 2014-04-07 7
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Reserved. Page 26 of 82
Mod. 0805 2011-07 Rev.2
6.2. Power Consumption
The GE866-QUAD preliminary power consumptions are:
GE866-QUAD
Mode
Average
(mA)
Mode description
SWITCHED OFF
Module power supplied only on VBATT_PA pin, the VBATT pin
is not power supplied.
Switched Off
Typical 2uA
max 20uA
Switched Off with
AT#SYSHALT
<500uA
Module power supplied on VBATT_PA pin and VBATT pin, the
command AT#SYSHALT is applied.
IDLE mode
AT+CFUN=1 9 Normal mode: full functionality of the module
AT+CFUN=4 9 Disabled TX and RX; module is not registered on the network
AT+CFUN=0 or =5
1.7
Paging Multiframe 2
1.5
Paging Multiframe 3
1.3 Paging Multiframe 4
0,8 Paging Multiframe 9
CSD TX and RX mode
GSM VOICE CALL GSM900 CSD PL5 200
DCS1800 CSD PL0
150
GPRS (class 1) 1TX + 1RX
GPRS Sending data mode GSM900 PL5 200
DCS1800 PL0 140
GPRS (class 10) 2TX + 3RX
GPRS Sending data mode GSM900 PL5 330
DCS1800 PL0
250
The GSM system is made in a way that the RF transmission is
not continuous, but it is packed into bursts at a base
frequency of approx. 217 Hz, and the relative current peaks
can be as high as about 2A. Therefore the power supply has to
be designed to withstand these current peaks without big
voltage drops; this means that both the electrical design and
the board layout must be designed for this current flow.
If the layout of the PCB is not well designed a strong noise
floor is generated on the ground and the supply; this will
reflect on all the audio paths producing an audible annoying
noise at approx. 217 Hz; if the voltage drop during the peak
current absorption is too much, then the device may even
shutdown as a consequence of the supply voltage drop.
NOTE: