SARA-G3 series - System Integration Manual
UBX-13000995 - R06
Objective Specification
System description
Page 28 of 218
Item
Requirement
Remark
VCC
peak current
Withstand the maximum peak current consumption
specified in the
SARA-G3 series Data
The specified maximum peak of current consumption
occurs during GSM single transmit slot in 850/900
MHz connected-mode, in case of mismatched antenna.
Section
current.
VCC
voltage drop
during Tx slots
Lower than 400 mV
VCC
voltage drop values greater than recommended
during 2G TDMA transmission slots directly affect the
RF compliance with applicable certification schemes.
VCC
voltage drop during
Tx slots.
VCC
voltage ripple
during Tx slots
Lower than 30 mVpp if f
ripple
≤
200 kHz
Lower than 10 mVpp if 200 kHz < f
ripple
≤
400
kHz
Lower than 2 mVpp if f
ripple
> 400 kHz
VCC
voltage ripple values higher than recommended
during 2G transmission directly affect the RF
compliance with applicable certification schemes.
VCC
voltage ripple during
Tx slots.
VCC
under/over-shoot
at start/end of Tx
slots
Absent or at least minimized
VCC
under/over-shoot higher than recommended at
the start/end of 2G TDMA transmission slots directly
affect the RF compliance with applicable certification
schemes.
VCC
voltage under/over-
shoot at the start/end of Tx slots
Table 6: Summary of VCC supply requirements
For the additional specific requirement for SARA-G350 ATEX modules integration in potentially
explosive atmospheres applications, refer to section 2.13.
1.5.1.2
VCC current consumption in connected-mode
When a GSM call is established, the
VCC
consumption is determined by the current consumption profile
typical of the GSM transmitting and receiving bursts.
The current consumption peak during a transmission slot is strictly dependent on the transmitted power,
which is regulated by the network. If the module is transmitting in GSM talk mode in the 850 or 900
MHz bands, at the maximum RF power control level (approximately 2 W or 33 dBm in the allocated
transmit slot/burst) the current consumption can reach up to 1900 mA (with a highly unmatched
antenna) for 576.9 µs (width of the transmit slot/burst) with a periodicity of 4.615 ms (width of 1
frame = 8 slots/burst), so with a 1/8 duty cycle according to GSM TDMA (Time Division Multiple
Access). If the module is in GSM connected-mode in the 1800 or 1900 MHz bands, the current
consumption figures are lower than the one in the 850 or 900 MHz bands, due to 3GPP transmitter
output power specifications (refer to
SARA-G3 series Data Sheet [1]).
During a GSM call, current consumption is in the order of 60-120 mA in receiving or in monitor bursts
and is about 10-40 mA in the inactive unused bursts (low current period). The more relevant factor for
determining the average current consumption, is the transmitted power in the transmit slot.
shows an example of the module current consumption profile versus time in GSM talk
mode.
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