Telit EVK2 User Guide
1vv0300704 Rev.13- 2012/06/25
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved
page
28 of 149
7.
Audio Section
7.1.
Overview
The Base Band chip of the Telit’s modules provides one or two (depends of model) audio
paths both in receive and in transmit sections, which could be active only one at time.
To turn on your well-suited section on EVK2, please refer to “
AF Amplifiers Setting
“paragraph and followings.
To know which are the suggested performances of the EVK2 audio transducers, refer to
“
Audio Accessories
“paragraph.
7.1.1.
History
The Baseband chip of our modules 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 (
Handset mode,
HS
) while the other couple of amplifiers must
be used with external audio transducers (
Handsfree mode,
HF
).
Transducers definitions:
Headsets
are transducers that receive an electrical signal from a receiver and use speakers
placed in close proximity to the ears to convert the signal into audible sound waves.
In the context of telecommunication, the word
Headset
is also commonly understood to refer
to a combination of
Headphone
and
Microphone
used for two-way communication, like with
a mobile phone.
Earphones
are small Headphones that are placed directly outside of the ear canal, but
without fully enveloping it. They are generally inexpensive and are favored for their
portability and convenience.
Earpiece
A part whether of a telephone receiver or hearing aid, that fits in or is held next to
the ear.
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