User's Manual
GE864
GE864GE864
GE864-
--
-QUAD Automotive V2 Hardware User Guide
QUAD Automotive V2 Hardware User GuideQUAD Automotive V2 Hardware User Guide
QUAD Automotive V2 Hardware User Guide
1vv0300840 Rev.3 2010-04-08
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 43 of 71
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.