TOBY-L2 and MPCI-L2 series - System Integration Manual
UBX-13004618 - R28
System description
Page 25 of 164
1.5.1.4
Current consumption in LTE connected-mode
During an LTE connection, the module can transmit and receive continuously due to the Frequency
Division Duplex (FDD) mode of operation used in LTE radio access technology.
The current consumption depends on output RF power, which is always regulated by the network (the
current base station) sending power control commands to the module. These power control
commands are logically divided into a slot of 0.5 ms (time length of one Resource Block), thus the rate
of power change can reach a maximum rate of 2 kHz.
The current consumption profile is similar to that in 3G radio access technology. Unlike the 2G
connection mode, which uses the TDMA mode of operation, there are no high current peaks since
transmission and reception are continuously enabled in FDD.
In the worst scenario, corresponding to a continuous transmission and reception at maximum output
power (approximately 250 mW or 24 dBm), the average current drawn by the module at the VCC pins
is considerable (see the “Current consumption” section in TOBY-L2 Data Sheet
or in MPCI-L2 Data
Sheet
). At the lowest output RF power (approximately 0.01
µ
W or –50 dBm), the current drawn by
the internal power amplifier is strongly reduced and the total current drawn by the module at the VCC
pins is due to baseband processing and transceiver activity.
shows an example of the module current consumption profile versus time in LTE connected-
mode. Detailed current consumption values can be found in TOBY-L2 Data Sheet
Data Sheet
Time
[ms]
Current [mA]
Current consumption
value depends on TX power
and actual antenna load
1 Slot
1 Resource Block
(0.5 ms)
1 LTE Radio Frame
(10 ms)
0
300
200
100
500
400
600
700
Figure 8: VCC or 3.3Vaux current consumption profile versus time during LTE connection (TX and RX continuously enabled)