ML865G1 HW Design Guide
1VV0301632 Rev. 4
Page
40
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86
2020-09-23
Unconditional Shutdown
HW_SHUTDOWN* is used to unconditionally shutdown the ML865G1
.
Whenever this
signal is pulled low, the ML865G1 is reset. When the device is reset it stops any
operation. After the release of the line, the ML865G1 is unconditionally shut down, without
doing any detach operation from the network where it is registered. This behaviour is not a
proper shut down because any cellular device is requested to issue a detach request on
turn off. The HW_SHUTDOWN* is internally controlled on start-up to achieve always a
proper power-on reset sequence, so there's no need to control this pin on start-up.
To unconditionally shutdown the ML865G1, the pad HW_SHUTDOWN* must be tied low
for at least 200 milliseconds and then released.
The signal is internally pulled up so the pin can be left floating if not used.
If used, then it
must always be connected with an open collector transistor
, to permit
to the internal circuitry the power on reset and under voltage lockout functions.
During PSM mode, HW_SHUTDOWN toggle has no effect. The use of HW_SHUTDOWN*
pin is valid only when ML865G1 has VAUX/PWRMON output HI.
PIN DESCRIPTION
Signal
Function
I/O
Pin
HW_SHUTDOWN*
Unconditional Shutdown of
the Module
I
55
WARNING:
The hardware unconditional Shutdown must not be used during
normal operation of the device since it does not detach the device
from the network. It shall be kept as an emergency exit procedure.
A typical circuit is the following:
