W681513 Datasheet, PDF (29/33 Pages) Winbond – 5V SINGLE-CHANNEL VOICEBAND CODEC FOR USB APPLICATIONS

W681513
11. TYPICAL APPLICATION CIRCUITS
LS1
SPEAKER
R1
1.5K
C2
R10 1K
C4 4.7uF
VCC
C1
0.1uF
MICROPHONE
R2
1.5K
1.0uF
C3
1.0uF
R3 1K
C6 330pF
R9
select
R4 1K
R5 91K
R6 91K
C7 330pF
R7 20K
R8 3K
U1
17 _AO
18 _AI-
19 _AI+
20
1
VAG
RO+
2 _RO+
6
VDD
FST
BCLKT
PCMT
14
12
13
MCLK ¹¹
PCMR
BCLKR
FSR
8
9
7
3 _PAI
4 _PAO-
5 _PAO+
u/A
16
10
PUI
VSS
C5 ^{W681513 15}
0.01uF
FRAME SYNC 8KHz INPUT
PCM OUTPUT
2.000 MHz MASTER CLOCK IN
PCM INPUT
PCM MODE CONTROL
POWER CONTROL
Figure 11.1 A USB VoIP Phone application
SUGGESTED COMPONENT VALUES BY APPLICATION
SCHEMATIC
COMPONENT #
TELEPHONE
HANDSET
VoIP PHONE SET
R3,4
R5,6
C6,7
R9
R7
R8
1K
27K
1200 pF
SELECT
20K
3K
1K
91K
330 pF
SELECT
20K
3K
In the handset application the gain from the handset microphone is set to 27 for the input amplifier.
This is because the acoustical chamber in the telephone type handset lets the electret microphone
provide an output of ~28 mV_RMS. The chamber typically has a gain of 3 over a bare microphone (or
one placed with only a small opening to the outside world.) Because of the high sensitivity of the
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Publication Release Date: October 1, 2003
Revision A3