Sony Ericsson GM29 - Manual (Page 6)

6 Electrical Connections
Electrical Connections
All electrical connections to the GM29 are
protected in compliance with the standard air
(4 kV) and contact (8kV) discharge ESD tests,
of EN 301 489-1.
The modem uses the following industry
standard connectors:
• RJ11 6-way (power connector)
• RJ9 4-way (audio connector)
• SIM card reader
• FME male coaxial jack (antenna
connector)
• Sub-D socket, 9 pin (RS232 serial port)
Power Connector
An RJ11 6-way connector, as shown and
described below, serves as a means of
supplying and controlling d.c. power to the
modem.
Connect positive power to VCC (pin 1) and the
ground or negative to GND (pin 6). VCC and
GND are reverse polarity and overvoltage
protected
NOTE! Application of the supply voltage
VCC, does not automatically switch
on the modem.
Switch on is usually achieved by use of the
TO_IN signal, which can be supplied by the
host application. Alternatively the modem can
be switched on at the same time that power is
applied by hard-wiring TO_IN to VCC. Refer
to “Switching On the Modem” on page 10 for
information on switch on methods.
Similarly the host application can be designed
to switch off the GM29 or perform a hard reboot
of the modem's software by use of the HR_IN
signal. Refer to “Switching Off the Modem”
and “Resetting the Modem” on page 10 for
additional information.
TO_IN and HR_IN are referenced to GND.
RJ11 Power Connector
Signal Description
VCC Positive power input
(5V to 32V d.c. at 1.5 A
max
)
TO_IN Active high control line used for
switching on the modem
(–0.5V to 32V;
V
IH
> 5V, V
IL
< 2 V)
HR_IN Active high control line used to
switch off or reset the modem
(–0.5V to 32V;
V
IH
> 5V, V
IL
< 2 V)
GND Negative power (ground) input
and return path for TO_IN and
HR_IN
6 5 4 3 2 1
1 VCC
2 n/c
3 HR_IN
4 TO_IN
5 n/c
6 GND