Integration Manual

SARA-R4/N4 series - System Integration Manual
UBX-16029218 - R13 System description Page 21 of 119
Figure 7 illustrates the current consumption profiles in GPRS connected mode, in 850 or 900 MHz bands, with 4 slots used
to transmit and 1 slot used to receive, as for the GPRS multi-slot class 12.
Time
[ms]
RX
slot
unused
slot
TX
slot
TX
slot
TX
slot
TX
slot
MON
slot
unused
slot
RX
slot
unused
slot
TX
slot
TX
slot
TX
slot
TX
slot
M ON
slot
unused
slot
GSM f ram e
4.615 m s
(1 f ram e = 8 slot s)
Current [A]
60-120 m A
GSM f ram e
4.615 m s
(1 f ram e = 8 slot s)
1.5
1.0
0.5
0.0
60-120 m A
10-40m A
20 0m A
Peak curr ent depends
on T X power and
act ual ant enna load
160 0 m A
Figure 7: VCC current consumption profile versus time during a GPRS multi-slot class 12 connection (4 TX slots, 1 RX slot)
In case of EGPRS (i.e. EDGE) connections, the VCC current consumption profile is very similar to the one during GPRS
connections: the current consumption profile in GPRS multi-slot class 12 connected mode illustrated in the Figure 7 is
representative for the EDGE multi-slot class 12 connected mode as well.
1.5.1.4 VCC current consumption in low power deep sleep mode (PSM enabled)
The power saving mode configuration is by default disabled, but it can be enabled using the AT+CPSMS command (see
the SARA-R4/N4 series AT Commands Manual [2] and section 1.13.9).
When power saving mode is enabled, the module automatically enters the PSM low power deep sleep mode whenever
possible, reducing current consumption down to a steady value in the µA range: only the RTC runs with internal 32 kHz
reference clock frequency.
Detailed current consumption values can be found in the SARA-R4/N4 series Data Sheet [1].
☞
☞☞
☞ Due to RTC running during PSM mode, the Cal-RC turns on the crystal every ~10 s to calibrate the RC oscillator, as a
consequence, a very low spike in current consumption will be observed.
1.5.1.5 VCC current consumption in low power idle mode (low power enabled)
The low power idle mode configuration is by default disabled, but it can be enabled using the AT+UPSV command (see
the SARA-R4/N4 series AT Commands Manual [2]).
When low power idle mode is enabled, the module automatically enters the low power mode whenever possible, but it
must periodically monitor the paging channel of the current base station (paging block reception), in accordance to the
2G / LTE system requirements, even if connected mode is not enabled by the application. When the module monitors the
paging channel, it wakes up to the active mode to enable the reception of the paging block. In between, the module
switches to low power mode. This is known as discontinuous reception (DRX) or extended discontinuous reception
(eDRX).
Detailed current consumption values can be found in the SARA-R4/N4 series Data Sheet [1].