SARA-N2 / N3 series - System integration manual
UBX-17005143 - R13
System description
Page 16 of 95
C1-Public
1.5.1.2
VCC current consumption profile
shows an example of the module
VCC
current consumption profile starting from the switch-
on event, followed by different phases and operating modes:
•
Network registration and context activation procedure
•
Transmission of an up-link datagram
•
RRC connection release and related signaling operations
•
Cyclic paging reception
•
Deep sleep mode
Timings in the figure are purely indicative since these may significantly change depending on the
network signaling activity. The current consumption peaks occur when the module is in the connected
(transmitting) mode and the value of these peaks is strictly dependent on the transmitted power,
which is regulated by the network. See the electrical specification section in the SARA-N2 series data
sheet
or SARA-N3 series data sheet
for more details about the current consumption values in
the different modes and the influence of the transmitting power level.
A proper power supply circuit for SARA-N2 / N3 series modules must be able to withstand the current
values present during the data transmission at maximum power, even though NB-IoT systems should
be designed to keep the module in deep-sleep mode for most of the time, with an extremely low
current consumption in the range of few microamps.
Cu
rr
en
t [
m
A]
200
1 50
1 00
50
0
5
1 0
1 5
20
25
30
40
35
Time [s]
Registration and
context activation
RRC connection release
(signaling operations)
Up-link
data
45
50
60
55
Cyclic paging reception
Deep Sleep
250
65
70
80
75
85
90
1 00
95
0
Figure 5: Example of module current consumption from the switch-on event up to deep-sleep mode
1.5.2
RTC supply (V_BCKP)
☞
The RTC supply (
V_BCKP
pin) is not available on SARA-N2 series modules.
V_BCKP
is the Real Time Clock (RTC) supply of SARA-N3 series modules. When
VCC
voltage is within
the valid operating range, the internal Power Management Unit (PMU) supplies the RTC and the same
supply voltage is available on the
V_BCKP
pin. If the
VCC
voltage is under the minimum operating limit
(e.g. during non powered mode), the RTC
can be externally supplied through the
V_BCKP
pin.
