Telit Communications S.p.A. GC864Q2 ユーザーズマニュアル
GC864 Hardware User Guide
1vv0300874 Rev.0 – 2010-01-25
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved.
Page 29 of 64
• The PCB traces from the input connector to the power regulator IC must
be wide enough to ensure no voltage drops 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 GC864-
QUAD V2 / GC864-DUAL V2, then this noise is not so disturbing and power
supply layout design can be more forgiving.
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 GC864-
QUAD V2 / GC864-DUAL V2, then this noise is not so disturbing and power
supply layout design can be more forgiving.
• The PCB traces to the GC864-QUAD V2 / GC864-DUAL V2 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.
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).
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
• 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.
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.
6.2.4.
Parameters for ATEX Applications
In order to integrate the Telit GC864-QUAD V2 / GC864-DUAL V2 module into an ATEX
application, the appropriate reference standard IEC EN xx and integrations shall be
followed.
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:
application:
• Total capacity: 27.45 uF
• Total inductance: 55.20 nH
• No voltage upper than supply voltage is present in the module.
• No step-up converters are present in the module.
• Total inductance: 55.20 nH
• No voltage upper than supply voltage is present in the module.
• No step-up converters are present in the module.