GE864-QUAD Automotive V2 Hardware User Guide
1vv0300840 Rev.0.1 24/11/09
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved
page 21 of 65
5.2 Power Consumption
The GE864-QUAD Automotive V2 power consumptions are:
GE864-QUAD Automotive V2
Mode
Average (mA)
Mode description
IDLE mode
Stand by mode; no call in progress
AT+CFUN=1
23,9
Normal mode: full functionality of the module
AT+CFUN=4
22
Disabled TX and RX; module is not registered on the
network
AT+CFUN=0 or
AT+CFUN=5
7,20 / 3,56
1
Power saving: CFUN=0 module registered on the network
and can receive voice call or an SMS; but it is not possible
to send AT commands; module wakes up with an
unsolicited code (call or SMS) or rising RTS line. CFUN=5
full functionality with power saving; module registered on
the network can receive incoming calls and SMS
RX mode
1 slot in downlink
52,3
2 slot in downlink
65,2
3 slot in downlink
78,6
4 slot in downlink
88,4
GSM Receiving data mode
GSM TX and RX mode
Min power level
78,1
Max power level
200,1
GSM Sending data mode
GPRS (class 10) TX and RX mode
Min power level
123,7
Max power level
370,8
GPRS Sending data mode
The GSM system is made in a way that the RF transmission is not continuous, else it is packed into
bursts at a base frequency of about 216 Hz, the relative current peaks can be as high as about 2A.
Therefore the power supply has to be designed in order to withstand with 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 216 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.
TIP: The electrical design for the Power supply should be made ensuring it will be capable of a peak current output
of at least 2A.
1
Worst/best case depends on network configuration and is not under module control
