Specifications

Product Technical Specification & Customer Design Guidelines
Interfaces
VREF
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WA_DEV_Q64_PTS_001-003 January 9, 2009
C5
Audio
ADC
Z2*= 12 0k O hm
typ
100nF
WMP100
(Inside Q64)
AUXI
AREF
59
C1MIC
R2
R1
60
Figure 18: Example of AUXI input single-ended connection without LC filter
*:Z2 is from 200Hz to 4kHz. For more characteristics refer to the chapter 3.11.1.1.2.
Recommended components:
 R1: 4K7 Ω ( for the bias voltage equal to 2.8V )
 R2: 820 Ω
 C1: 12pF to 33pF (needs to be tuned depending on the design )
 C2: Need to be tuned depending on the design.
 C5 : 2.2uF +/- 10%
 L1: Need to be tuned depending on the design.
Since AUXI is very sensitive to audio noise, it is strongly recommended to use VREF
(pin 34) for voltage biasing or to ensure to use a “clean” source.
CAUTION
: If VREF is not used TDMA noise can degrade quality.
The capacitor C1 is highly recommended to reduce the TDMA noise. C1 must be
close to the microphone.