Texas Instruments PCM2704, Руководство пользователя

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Typical Circuit Connection 2 (Example of Remote Headphone)
External ROM
(3)
(Optional)
SDA
V
BUS
D+
GND
SCL
USB ’B’
Connector
D–
C
8
R
1
SUSPEND
R
7
R
8
Headphone
31 30 29 28 27
FSEL TEST S
SPND
XTI XTO CK DT
PSEL
(2)
V
CO
M
AGNDR
V
CCR
V
OU
T
R
(1)
V
OU
T
L
(1)
V
CCL
AGNDL
ZGND
32 26
PGND
V
CCP
(3)
HOST
(2)
FUNC3
FUNC0
HID0/MS
HID1/MC
HID2/MD
PCM2706PJT
25
23
22
21
20
19
24
18
17
10 11 12 13 14 91 5 16
2
3
4
5
6
1
7
8
V
BUS
D+
D–
V
DD
DGND
FUNC1
FUNC2
DOUT
C
5
+
C
6 C
3
C
4
X
1
C
1
C
2
R
11
+
C
9
+
C
10
R
9
R
10
C
11
R
5
C
12
R
6
C
7
R
2
R
3
R
4
PLAY/PAUSE
NEXT TRACK
MUTE
VOLUME–
PREVIOUS TRACK
STOP
PCM2704
,,
PCM2705
PCM2706, PCM2707
www.ti.com ....................................................................................................................................................... SLES081F – JUNE 2003 – REVISED JANUARY 2009
Figure 33 illustrates a typical circuit connection for a bus-powered, 100-mA headphone with seven HIDs.
NOTE: X
1
: 12-MHz crystal resonator. C
1
, C
2
: 10-pF to 33-pF capacitors (depending on load capacitance of crystal resonator). C
3
-C
5
, C
7
, C
8
:
1-
µ
F ceramic capacitors. C
6
: 10-
µ
F electrolytic capacitor. C
9
, C
10
: 100-
µ
F electrolytic capacitors (depending on required frequency response).
C
11
, C
12
: 0.022-
µ
F ceramic capacitors. R
1
: 1 M Ω resistor. R
2
, R
11
: 1.5 k Ω resistors. R
3
, R
4
: 22 Ω resistors. R
5
, R
6
: 16 Ω resistors. R
7
-R
10
: 3.3
k Ω resistors.
(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
CCP
, but any other active component must not use V
CCP
, V
CCL
, V
CCR
, or V
DD
as a power
source.
Figure 33. Bus-Powered Application
NOTE:
The circuit illustrated in Figure 33 is for information only. The entire board design
should be considered to meet the USB specification as a USB-compliant product.
Copyright © 2003–2009, Texas Instruments Incorporated
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