Audio Interface - Sierra Wireless MC5725 Hardware Integration Manual

4: Audio Interface

Note: Values in this guide are
taken from the appropriate
product specification documents
(PSDs) (listed in
documents
, page
case of a discrepancy between
this document and the relevant
PSD, use the value listed in the
PSD.
Table 4-1: Audio features
Gain (adjustable)
Filtering stages
Noise suppression
Echo cancellation
Output driver stage
FIR (Finite Impulse
Response) filtering
Audio pass band
Rev 1.9.1 Feb.09
In the event of a discrepancy in values between this guide and the Product Specification Document (PSD), the PSD takes precedence.
The MC5725V / M C5727V / MC5728V / M C8775V / M C8785V /
M C8790V / M C8791V / M C8792V modules support four audio
modes that may be required by a host audio system:
Related
Handset
•
13) — in the
• Headset
Car kit
•
Speakerphone
•
The modules support both a differential analog interface and
PCM digital audio, and allow dynamic run‐time selection of
the appropriate mode.
Table 4‐1 summarizes the key audio features of these modules.
Feature
MC5725V / MC5727V — Up to
+16 dB analog gain
MC5728V — Programmable to 0 dB
or +24 dB
MC8775V / MC8785V / MC8790V /
MC8791V / MC8792V — Up to
+48.5 dB analog gain available
(when the analog interface is
selected)
Several adjustable high-pass and
slope filters
Supported
Configurable for each audio mode
(headset, handset, speakerphone,
and car kit)
n/a
MC87xx — Option of providing 13 tap FIR filtering for receive and
transmit paths to equalize the acoustic response of the speaker
and microphone elements.
300 Hz–3.4 kHz
These modules are intended to serve as an integral component
of a more complex audio system—for example, a PDA with a
separate codec interfaced to the Host Application processor.
Proprietary and Confidential
Transmit
Up to +12 dB
High-pass filter
n/a
n/a
Supported
4
Receive
51