User's Manual

GE/GC864-QUAD V2 and GE864-GPS Hardware User Guide
1vv0300915 Rev.2 – 2011-06-15
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights
Reserved. Page 44 of 97
occur when the 2A current peaks are absorbed. Note that this
is not made in order to save power loss but especially to
avoid the voltage drops on the power line at the current
peaks frequency of 216 Hz that will reflect on all the
components connected to that supply, introducing the noise
floor at the burst base frequency. For this reason while a
voltage drop of 300-400 mV may be acceptable from the power
loss point of view, the same voltage drop may not be
acceptable from the noise point of view. If your application
does not have audio interface but only uses the data feature
of the Telit GE/GC864-QUAD V2 and GE864-GPSthen this noise is
not so disturbing and power supply layout design can be more
forgiving.
• The PCB traces to the GE/GC864-QUAD V2 and GE864-GPS and the
Bypass capacitor must be wide enough to ensure no significant
voltage drops occur when the 2A current peaks are absorbed.
This is for the same reason as previous point. Try to keep
this trace as short as possible.
• The PCB traces connecting the Switching output to the
inductor and the switching diode must be kept as short as
possible by placing the inductor and the diode very close to
the power switching IC (only for switching power supply).
This is done in order to reduce the radiated field (noise) at
the switching frequency (100-500 kHz usually).
• The use of a good common ground plane is suggested.
• The placement of the power supply on the board must be done
in such a way to guarantee that the high current return paths
in the ground plane are not overlapped to any noise sensitive
circuitry as the microphone amplifier/buffer or earphone
amplifier.
• The power supply input cables must be kept separate from
noise sensitive lines such as microphone/earphone cables.
6.3.4. Parameters for ATEX Applications
In order to integrate the Telit’s modules into an ATEX
application, the appropriate reference standard IEC EN xx and
integrations shall be followed.
Below are listed parameters and useful information to
integrate the module in your application:
GE864-QUAD V2
• Total capacity: 27.45 uF