Rev 1.9.1 Feb.09
Proprietary and Confidential
19
In the event of a discrepancy in values between this guide and the Product Specification Document (PSD), the PSD takes precedence.
•
Low power (“airplane mode”)
The
module
is
active,
but
RF
is
disabled.
State
machines
are
implemented
in
the
module
to
monitor
the
power
supply
and
operating
temperature.
Disconnected state
Note: The difference between
the Disconnected and Off states
is that, in the Off state, the
module is still connected to the
power source and draws minimal
current.
This
state
occurs
when
there
is
no
power
to
the
module
—
the
host
power
source
is
disconnected
from
the
module
and
all
voltages
associated
with
the
module
are
at
0
V.
Whether
the
host
device
is
also
powered
off
depends
on
the
power
rail
design.
If
the
connection
between
the
power
rail
and
the
module
is
controlled
by
the
host,
the
host
can
stay
powered
on
and
cut
the
power
to
put
the
modem
into
the
disconnected
state.
If
the
power
rail
is
shared
between
the
host
device
and
the
module,
the
host
is
powered
off
when
the
module
is
powered
off.
Off state
Note: The module enters the Off
state if W_Disable# is driven low
and power (Vcc) is applied to the
module, or if the module is in a
powered state and W_Disable#
is driven low for a module-
dependent minimum period. See
on
for details.
In
this
state,
the
host
is
powered
up
and
the
module
is
powered
down
(but
still
connected
to
the
power
source).
The
host
keeps
the
module
powered
off
by
driving
the
W_Disable#
signal
low.
In
this
state,
the
module
draws
minimal
current.
Normal state
Note: This is the default state
when VCC3.3 is first applied in
the absence of W_Disable#
control.
This
is
the
active
state
of
the
module.
In
this
state:
•
The
module
is
fully
powered.
•
The
module
is
capable
of
placing
/
receiving
calls
or
estab
‐
lishing
data
connections
on
the
wireless
network.
•
The
USB
interface
is
fully
active.
Low power mode
In
this
state,
RF
(both
Rx
and
Tx)
is
disabled
in
the
module,
but
the
USB
interface
is
still
active.
This
low
power
mode
(
ʺ
airplane
mode
ʺ
)
is
controlled
by
software
commands
through
the
host
interface.