Texas Instruments PCM2704, Руководство пользователя

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Typical Circuit Connection 1 (Example of USB Speaker)
TEST0
XTO 28
27
26
25
24
23
22
21
20
19
1
2
3
4
5
6
7
8
9
10
PCM2704DB
CK
DT
PSEL
(2)
DOUT
DGND
V
DD
D–
D+
V
BUS
SSPND
HOST
(2)
XTI
TEST1
HID2/MD
PGND
V
CCP
(3)
HID0/MS
HID1/MC
External ROM
(3)
(Optional)
SCL
11
12
13
14
ZGND
AGNDL
V
CCL
V
OUT
L
(1)
18
17
16
15
AGNDR
V
CCR
V
OUT
R
(1)
V
COM
R
9
C
4
D–
D+
GND
R
1
C
2
X
1
C
1
SDA
S/PDIF OUT
C
7
R
2
USB ’B’
Connector
V
BUS
C
3
R
3
R
4
C
6
SUSPEND
C
5
+
C
8
+
C
9
+
C
10
C
11
R
5
C
12
R
6
R
7
R
8
TPA200X
Power
Amp
VOLUME–
MUTE
C
13
+
C
14
+
PCM2704
,,
PCM2705
PCM2706, PCM2707
SLES081F – JUNE 2003 – REVISED JANUARY 2009 ....................................................................................................................................................... www.ti.com
Figure 32 illustrates a typical circuit connection for an internal-descriptor, bus-powered, 500-mA application.
NOTE: X
1
: 12-MHz crystal resonator. C
1
, C
2
: 10-pF to 33-pF capacitor (depending on load capacitance of crystal resonator). C
3
-C
7
: 1-
µ
F
ceramic capacitor. C
8
: 10-
µ
F electrolytic capacitor. C
9
, C
10
: 100-
µ
F electrolytic capacitor (depending on tradeoff between required frequency
response and discharge time for resume). C
11
, C
12
: 0.022-
µ
F ceramic capacitor. C
13
, C
14
: 1-
µ
F electrolytic capacitor. R
1
: 1 M Ω resistor. R
2
,
R
9
: 1.5 k Ω resistors. R
3
, R
4
: 22 Ω resistors. R
5
, R
6
: 16 Ω resistors. R
7
, R
8
: 330 Ω resistors (depending on tradeoff between required THD
performance and pop-noise level for suspend).
(1) Output impedance of V
OUT
L and V
OUT
R during suspend mode or lack of power supply is 26 k Ω ±20%, which is the discharge path for C
9
and C
10
.
(2) Descriptor programming through external ROM is only available when PSEL and HOST are high.
(3) External ROM power can be supplied from V
CC
P, but any other active component must not use V
CCP
, V
CCL
, V
CCR
, or V
DD
as a power
source.
Figure 32. Bus-Powered Application
NOTE:
The circuit illustrated in Figure 32 is for information only. The entire board design
should be considered to meet the USB specification as a USB-compliant product.
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