SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R26
System description
Page 24 of 217
1.5
Supply interfaces
1.5.1
Module supply input (VCC)
The modules must be supplied via the three
VCC
pins that represent the module power supply input.
The
VCC
pins are internally connected to the RF power amplifier and to the integrated Power Management Unit:
all supply voltages needed by the module are generated from the
VCC
supply by integrated voltage regulators,
including the
V_BCKP
Real Time Clock supply,
V_INT
digital interfaces supply and
VSIM
SIM card supply.
During operation, the current drawn by the SARA-G3 and SARA-U2 series modules through the
VCC
pins can
vary by several orders of magnitude. This ranges from the high peak of current consumption during GSM
transmitting bursts at maximum power level in connected mode (as described in section 1.5.1.2) to the low
current consumption during low power idle mode with power saving enabled (as described in section 1.5.1.4).
SARA-G3 modules, versions “02” onwards, provide separate supply inputs over the three
VCC
pins:
VCC
pins #52 and #53 represent the supply input for the internal RF power amplifier, demanding most of
the total current drawn of the module when RF transmission is enabled during a voice/data call
VCC
pin #51 represents the supply input for the internal baseband Power Management Unit and the internal
transceiver, demanding a minor part of the total current drawn of the module when RF transmission is
enabled during a voice/data call
The following Figure 7 and Figure 8 provide a simplified block diagram of SARA-G3 and SARA-U2 series modules
internal VCC supply routing.
53
VCC
52
VCC
51
VCC
SARA-U2 series
Power
Management
Unit
Memory
Baseband
Processor
Transceiver
RF PMU
PA PMU
3G PA
2G PA
Figure 7: SARA-U2 module VCC supply simplified block diagram
53
VCC
52
VCC
51
VCC
SARA-G3 series
(product versions ‘00’ and ’01’)
Power
Management
Unit
Memory
Baseband
Processor
Transceiver
RF PMU
2G PA
53
VCC
52
VCC
51
VCC
SARA-G3 series
(product versions ‘02’ onwards)
Power
Management
Unit
Memory
Baseband
Processor
Transceiver
RF PMU
2G PA
Figure 8: SARA-G3 module VCC supply simplified block diagram (product versions “00” / “01” versus product version “02”)
