User's Manual
GE864
GE864GE864
GE864-
--
-QUAD V2 / GE864
QUAD V2 / GE864QUAD V2 / GE864
QUAD V2 / GE864-
--
-DUAL V2 Hardware User Guide
DUAL V2 Hardware User GuideDUAL V2 Hardware User Guide
DUAL V2 Hardware User Guide
1vv0300875 Rev.1 – 2010-03-29
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved. Page 44 of 73
10. Audio Section Overview
The first Baseband chip was developed for the cellular phones, which needed two
separated amplifiers both in RX and in TX section.
A couple of amplifiers had to be used with internal audio transducers while the other
couple of amplifiers had to be used with external audio transducers.
To distinguish the schematic signals and the Software identifiers, two different
definitions were introduced, with the following meaning:
• internal audio transducers
HS
HSHS
HS/MT
(from
H
HH
HandS
SS
Set
or
M
MM
MicroT
TT
Telephone
)
• external audio transducers
HF
HFHF
HF
(from H
HH
HandsF
FF
Free )
Actually the acronyms have not the original importance.
In other words this distinction is not necessary, being the performances between the
two blocks like the same.
Only if the customer needs higher output power to drive the speaker, he needs to
adopt the Aduio2 Section (
HF
) . Otherwise the choice could be done in order to
overcome the PCB design difficulties.
For these reasons we have not changed the
HS
and
HF
acronyms, keeping them in
the Software and on the schematics.
The Base Band Chip of the GE864-QUAD V2 / GE864-DUAL V2 Telit Modules
maintains the same architecture.
For more information and suggestions refer to Telit document:
• Audio settings application note , 80000NT10007a
10.1.
10.1.10.1.
10.1. Selection mode
Selection mode Selection mode
Selection mode
Only one block can be active at a time, and the activation of the requested audio
path is done via hardware ,by
AXE
AXEAXE
AXE
line, or via software ,by
AT#CAP
AT#CAPAT#CAP
AT#CAP
command .
Moreover the
Sidetone
SidetoneSidetone
Sidetone
functionality could be implemented by the amplifier fitted
between the transmit path and the receive path, enabled at request in both modes.