SIM340 Hardware Design
3 Application interface
SIM340 is equipped with a 60-pin 0.5mm pitch board-to-board connector that connects to the
cellular application platform. Sub-interfaces included in this board-to-board connector are
described in detail in following chapters:
Power supply (
Serial interfaces
(please refer to
)
Two analog audio interfaces
)
SIM interface
)
Electrical and mechanical characteristics of the board-to-board connector are specified in
Chapter 6.
There we also include order information for mating connectors.
3.1 SIM340 pin description
Table
5
: Board-to-Board connector pin description
Power Supply
PIN NAME I/O
DESCRIPTION
DC CHARACTERISTICS COMMENT
VBAT
I
8 VBAT pins of the board-to-board
connector are dedicated to connect
the supply voltage. The power
supply of SIM340 has to be a
single voltage source of VBAT=
3.4V...4.5V. It must be able to
provide sufficient current in a
transmitting burst which typically
rises to 2A.mostly. These 8 pins are
voltage input
Vmax= 4.5V
Vmin=3.4V
Vnorm=4.0V
VRTC
I/O
Current input for RTC when the
battery is not supplied for the
system.
Current output for backup battery
when the main battery is present
and the backup battery is in low
voltage state.
Vmax=2.0V
Vmin=1.2V
Vnorm=1.8V
I
out(max)
= 20uA
I
in
=5 uA
Do not keep
pin open, it
should be
connected to a
battery or a
capacitor.
VDD_EXT
O
Supply 2.93V voltage for external
circuit. By measuring this pin, user
can judge whether the system is
power on or off. When the voltage
is low, the system is power off.
Vmax=3.0V
Vmin=2.75V
Vnorm=2.93V
Imax=10mA
If unused
keep pin open
SIM340_HD_V3.09
18.03.2009
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