LE910Cx HW User Guide
1VV0301298 Rev. 33
Page 47 of 128
2021-06-29
Not Subject to NDA
Note: Do not use any pull-up resistor on the HW_SHUTDOWN_N line
or any totem pole digital output. Using a pull-up resistor may cause
latch-up problems on the LE910Cx power regulator and improper
functioning of the module. The HW_SHUTDOWN_N line must be
connected only in an open-collector configuration.
Note: The Unconditional Hardware Shutdown must always be
implemented on the boards, but this function must use it only as an
emergency exit procedure, and not as a normal power-off operation.
Powering OFF the Module
Powering OFF the module should be done gracefully allowing the module to complete all
ongoing and pending tasks while properly handling all memory buffers.
In a complete power supply shut down is needed, the below procedure must be followed:
1.
Perform a HW shutdown as described in Section 5.3.1
2.
Wait for the HW Shutdown procedure to complete (monitor the PWRMON/SW_RDY
pin).
3.
Turn OFF power supply to the module
Warning: Carefully
follow the recommended procedure for shut down
and power off.
Failure to follow the recommended shut-down and power off
procedures might damage the device and consequently void the
warranty.
Fast Power Down
The gentle power down procedure is described in chapter 5.3.1 and 5.3.2. It normally
takes more than 15 seconds to de-attach network and make LE910Cx internal filesystem
properly closed.
In the event of an unwanted power supply loss, LE910Cx can be switched off without any
risk of filesystem data corruption by implementing Fast Power Down feature.
The Fast Power Down feature permits to reduce the current consumption and the time-
to-power off to minimum values.