GL865-DUAL V3 Hardware User Guide
1vv0301018 Rev.5 – 2013-08-05
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights Reserved.
Page 25 of 76
Mod. 0805 2011-07 Rev.2
6.2.
Power Consumption
The GL865-DUAL V3 power consumptions are:
GL865-DUAL V3
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
10
Normal mode: full functionality of the module
AT+CFUN=4
10
Disabled TX and RX; module is not registered on the network
AT+CFUN=0 or =5
2
Paging Multiframe 2
1.7
Paging Multiframe 3
1,5
Paging Multiframe 4
0,9
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:
The electrical design for the Power supply should be made ensuring it will be capable of a
peak current output of at least 2 A.