User's Guide
UC864-E-AUTO / AWS-AUTO Hardware User Guide
1vv0300795 Rev.11 – 2010/11/18
Reproduction forbidden without Telit Communications S.p.A’s. written authorization - All Rights Reserved. Page 48 of 78
11. Audio Section Overview
Audio Section OverviewAudio Section Overview
Audio Section Overview
The
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/MT
HS/MTHS/MT
HS/MT
(from
H
HH
HandS
SS
Set
or
M
MM
MicroT
TT
Telephone
)
• external audio transducers
HF
HF HF
HF
(from HandsFree )
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 yhe customer needs higher output power to the speaker , he has a constraint. 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 UC864-E-AUTO / AWS-AUTO Telit Module maintains the same
architecture.
For more information refer to Telit document:
„
80000NT10025a UC864 Audio Settings Application Note
80000NT10025a UC864 Audio Settings Application Note80000NT10025a UC864 Audio Settings Application Note
80000NT10025a UC864 Audio Settings Application Note“
.
11.1.
Selecti
SelectiSelecti
Selection mode
on modeon mode
on 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
.