Specifications

WM_PRJ_Q2501_PTS_001 – 003
March 2004
© 2003 All rights reserved
Page:
44
/
93
This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged without prior written
agreement.
Ce document est la propriété exclusive de WAVECOM. Il ne peut être communiqué ou divulgué à des tiers sans son
autorisation préalable.
Signal Pin # I/O I/O type Description
COL2 47 I/O CMOS / 1X Column scan
COL3 49 I/O CMOS / 1X Column scan
COL4 51 I/O CMOS / 1X Column scan
2.6.6 Audio interface
Two different microphone inputs (MIC1 and MIC2) and two different speaker
outputs (SPK1 and SPK2) are supported.
Main audio interface is made up of MIC2 inputs (microphone) and SPK2 outputs
(speaker).
Auxiliary audio interface is made up of MIC1 inputs (microphone) and SPK1
outputs (SPK1). Auxiliary audio interface is appropriate for a hands-free system
or a handset with biasing external to the module.
The WISMO Quik Q2501 module also includes echo cancellation and noise
reduction features improving quality of hands-free function.
In some cases, ESD protection must be added on the audio interface lines.
2.6.6.1 Microphone inputs
2.6.6.1.1 General description
The main microphone inputs (MIC2) already include the biasing for an electret
microphone allowing an easy connection to a handset.
The auxiliary microphone inputs (MIC1) do not include an internal bias.
For both microphone paths the connection can be either differential or single-
ended but using a differential connection in order to reject common mode noise
and TDMA noise is strongly recommended.
The use of a single-ended connection requires a very good ground plane, a very
good filtering as well as shielding in order to avoid any disturbance on the audio
path.
2.6.6.1.2 Main Microphone Inputs (MIC2)
MIC2 inputs include an internal convenient biasing for an electret microphone.
This electret microphone can be directly connected on these inputs, either in
differential or single-ended mode.
The gain is internally adjusted through AT commands.
AC coupling is already embedded in the module.
Pin description
Signal Pin # I/O I/O type Description
MIC2P 66 I Analog Microphone 2 positive input
MIC2N 68 I Analog Microphone 2 negative input