User's Manual

LE910 V2 HARDWARE USER GUIDE 1VV0301200 Rev.2 Preliminary • 2015-08-04 38 of 81

5.4 Unconditional Shutdown

HW_SHUTDOWN* is used to unconditionally shutdown the LE910 V2. Whenever this signal is pulled low, the

LE910 V2 is reset. When the device is reset it stops any operation. After the release of the line, the LE910 V2 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 WCDMA 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 LE910 V2, 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.

PIN DESCRIPTION

Signal

Function

I/O

PAD

HW_SHUTDOWN*

Unconditional Shutdown of the Module

R13

OPERATING LEVELS

Signal Status

Min

Max

HW_SHUTDOWN* Input high

1.5V

1.9V

HW_SHUTDOWN* Input Low

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.