Specifications

Product Technical Specification & Customer Design Guidelines
Interfaces
The capacitor C1 is highly recommended to eliminate the TDMA noise. C1 must be
close to the microphone.
Recommended components:
 C1: 12pF to 33pF (needs to be tuned depending on the design )
 C2: Need to be tuned depending on the design.
 L1: Need to be tuned depending on the design.
3.11.4.1.3 AUXI connection example
VREF
Audio
ADC
Z2*= 120k O hm
typ
100nF
WMP100
(Inside Q64)
AUXI
AREF
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This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged without
prior written agreement.
WA_DEV_Q64_PTS_001-003 January 9, 2009
C5
59
L1
C2
C1MIC
R2
R1
60
Figure 17: Example of AUXI input single-ended connection with LC filter
*:Z2 is from 200Hz to 4kHz. For more characteristics refer to chapter 3.11.1.1.2.
While using a single-ended connection in AUXI, ensure to have a good ground plane,
a good filtering and shielding, in order to avoid any disturbance on the audio path. It
is recommended to use the Q64 Wireless CPU
®
AREF pin for good plane connection.
It is recommended to add L1 and C2 footprint to add a LC EMI filter to try to eliminate
the TDMA noise.
When not used, the filter can be removed by replacing L1 by a 0 Ω resistor and by
disconnecting C2, as shown in the following schematic.