User's Manual

UE866 HARDWARE USER GUIDE 1vv0301157 Rev.7 • 2015-04-17 30 of 68
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5.4 Reset
To unconditionally reboot the UE866, the pad RESET* must be tied low for at least 200 milliseconds
and then released.
The maximum current that can be drained from the RESET* pad is 0,15 mA.
The hardware unconditional Restart 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 to be
done in the rare case that the device gets stuck waiting for some network or SIM responses.
Do not use any pull up resistor on the RESET* line nor any totem pole digital output. Using pull up
resistor may bring to latch up problems on the UE866 power regulator and improper functioning of the
module.
The line RESET* must be connected only in open collector configuration; the transistor must be
connected as close as possible to the RESET* pin.
The unconditional hardware restart must always be implemented on the boards and the software must
use it as an emergency exit procedure.
PIN DESCRIPTION
Signal
Function
I/O
PAD
RESET*
Unconditional Shutdown of the Module
I
G4
OPERATING LEVELS
Signal Status
Min
Max
RESET* Input high
1.5V
1.9V
RESET* Input Low
0V
0.35V
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.