User's Manual

LE920A4 HW User Guide Hardware Commands
Doc#: 1VV0301261 Turning off the Module
Rev. 4.3 Page 49 of 123 2017-12-07
5.3.1. Shutdown by Software Command
The module can be shut down by a software command.
When a shutdown command is sent, the module goes into the Finalization state and at the
end of the finalization process shuts down PWRMON. The duration of the finalization state
can differ according to the current situation of the module, so a value cannot be defined.
Usually, it will take more than 15 seconds from sending a shutdown command until
reaching a complete shutdown. The DTE should monitor the status of PWRMON to
observe the actual power-off.
Figure 5: Shutdown by Software Command
NOTE:
To check whether the device has powered off, monitor the PWRMON
hardware line. When PWRMON goes low, the device has powered off.
5.3.2. Hardware Shutdown
To turn off the module, the ON/OFF pad must be asserted low for at least 2.5 seconds
and then released. Use the same circuitry and timing for power-on.
When the hold time of ON/OFF is above 2.5 seconds, the module goes into the
Finalization state and in the end shuts down PWRMON.
The duration of the Finalization state can differ according to the current situation of the
module, so a value cannot be defined.
Usually, it will take more than 15 seconds from sending a shutdown command until
reaching a complete shutdown. DTE should monitor the status of PWRMON to observe
the actual power-off.