Xplore Technologies Corp. MC7750 Manual Do Utilizador

Electrical Specifications

Rev 4  Sep.11

Proprietary and Confidential - Contents subject to change

33

The MC7750 provides signals for:

Power control of the module from the host

LED driver output

These signals are summarized in 

and paragraphs that follow.

The host device uses 

W_DISABLE_N

 (pin 20) to enable / disable the WWAN or 

radio modem. When disabled, the modem cannot transmit or receive information.

Letting this signal float high allows the module to operate normally. This switch 
follows the behavior described in [11] PCI Express Mini Card Electromechanical 
Specification Revision 1.2. This pin has a 20 k

 pull-up resistor. See 

on page 33 for a recommended implementation.

When integrating with your host device, keep the following in mind:

The signal is an input to the module and should be driven LOW only for its 
active state (controlling the power state); otherwise it should be floating or 
(High impedance). It should never be driven to a logic high level. The module 
has an internal pull-up resistor to Module Power (3.3V) in place, so if the 
signal is floating or (high impedance), the module will power on.

Wait for two seconds after asserting W_DISABLE_N before disconnecting 
power.

If the host never needs to assert this power state control to the module, leave 
this signal unconnected from the host interface.

1.

O — Digital pin Output; PU — Digital pin Input, internal pull up

W_DISABLE_N

20

Wireless disable (Main RF)

PU

WLAN_LED_N

42

LED driver

O

MiniCard

R

Wireless 

disable control

1

2

3

Q

20k

Host

3.3V

PMIC for W_DISABLE_N