Product Info

LTE Module Series
EC21 Hardware Design
EC21_Hardware_Design
3-29
/ 105
Minimum
Functionality
Mode
AT+CFUN command can set the module to a minimum functionality mode without
removing the power supply. In this case, both RF function and (U)SIM card will be invalid.
Airplane
Mode
AT+CFUN command or W_DISABLE# pin can set the module to airplane mode. In this
case, RF function will be invalid.
Sleep Mode
In this mode, the current consumption of the module will be reduced to the minimal level.
During this mode, the module can still receive paging message, SMS, voice call and
TCP/UDP data from the network normally.
Power down
Mode
In this mode, the power management unit shuts down the power supply. Software is not
active. The serial interface is not accessible. Operating voltage (connected to VBAT_RF
and VBAT_BB) remains applied.
3.4. Power Saving
3.4.1. Sleep Mode
EC21 is able to reduce its current consumption to a minimum value during the sleep mode. The following
section describes power saving procedures of EC21 module.
3.4.1.1. UART Application
If the host communicates with module via UART interface, the following preconditions can let the module
enter into sleep mode.
 Execute AT+QSCLK=1 command to enable sleep mode.
 Drive DTR to high level.
The following figure shows the connection between the module and the host.
Figure 3: Sleep Mode Application via UART