User's Manual

LE940B6 Hardware User Guide
1VV0301331 Rev. 1.8 - 2017-03-15
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5.3.2. Hardware Shutdown
To turn off the LE940B6 module, the ON_OFF_N pad must be asserted low in the range of 1150 -
1250 milliseconds and then released. Use the same circuitry and timing for power-on.
When the ON_OFF_N is asserted low for a period in the range 1150 - 1250 milliseconds and then
released, LE940B6 goes into the Finalization state and in the end shuts down VAUX/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 6 seconds from sending a shutdown command until reaching a
complete shutdown. The DTE host should monitor the status of VAUX/PWRMON to observe the
actual power-off.
Figure 8: Hardware Shutdown
OFF State
Internal State
VAUX/PWRMON
VBATT
Activation State
Variable Above
6 sec
Monitoring Status
ON_OFF_N
1150ms < Hold Time < 1250ms
Finalization State
NOTE:
To check whether the device has powered off, monitor the VAUX/PWRMON hardware line.
When VAUX/PWRMON goes low, the device has powered off.