Disconnected State; Off State; Normal State; Low Power Mode - Sierra Wireless MC5725 Hardware Integration Manual

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.
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
State change: Power off / on
page 23 for details.
Note: This is the default state
when VCC3.3 is first applied in
the absence of W_Disable#
control.
Rev 1.9.1 Feb.09
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

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

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
signal low. In this state, the module draws minimal
W_Disable#
current.
on

Normal state

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
(ʺairplane modeʺ) is controlled by software commands
through the host interface.
Proprietary and Confidential
Power Interface
19