Rev 1.0
1/27/14
16
16
Reference Guide
Interfaces
Figure 5.
Power Supply Connector
Refer to the following table for the pin description of the power supply connector.
Table 2.
Power Supply Connector Pin Description
Pin #
Signal
Description
1
GPIO25/INT1
General purpose input/output or Interrupt
2
GPIO35
General purpose input/output
3
Vref
Voltage reference for the GPIOs
4
Reserved
Reserved
5
Reserved
Reserved
6
GND
Ground
7
DC-IN
Input Supply for the modem (4.75V to 32V)
8
ON/OFF
Control pin to power OFF the modem
9
Reserved
Reserved
10
Reserved
Reserved
The input voltage range (DC-IN) is from 4.75V to 32V, with a typical operating
voltage of 13.2V.
Caution:
Pins 1, 2, 3, 4, 5, 8, 9 and 10 are low voltage interfaces. It is strictly prohibited to connect these pins
to any power supply as there is a risk of damaging the modem.
3.1.1.1.
General Purpose Input/Output
The modem has two external GPIO ports:
•
GPIO35
and
•
GPIO25;
as well as a voltage reference line,
Vref
.
Vref
sets the reference voltage of the input or output of the two GPIOs. Leaving it
unconnected sets the GPIO level at 2.3V – 2.6V by default. It is
strongly
recommended to connect to the required GPIOs’ output voltage (2.8V ~ 15V).