WM8740 25 External Components Diagram Application Circuit

Part No :
WM8740 circuit
File Size : 63 KB
Pages : 27 Pages

Other Part Numbers in this pdf file

WM8740SEDS-RV   WM8740EDS-V  
Wolfson Microelectronics plc

find WM8740 datasheet
WM8740 circuit
WM8740
APPLICATIONS INFORMATION
RECOMMENDED EXTERNAL COMPONENTS
DVDD
C
1
+
C
2
8
15
9
20
+
14
10
19
16
17
13
12
+
-
+
-
AGND
C
3
C
4
C
5
C
6
AVDD
Production Data
DVDD
AVDD
AVDDR
7
DGND
AVDDL
DGND
AGND
AGNDR
AGNDL
28
27
ML/I2S
MC/DM1
MD/DM0
CSB/IWO
RSTB
VOUTLN
VOUTLP
VOUTRN
VOUTRP
LEFT OUTPUT DATA
Software I/F or
Hardware Control
26
23
22
RIGHT OUTPUT DATA
4
MODE8X
6
WM8740
DIFFHW
21
AVDD
R
1
24
MODE
ZERO
25
MUTEB
VMIDR
VMIDL
11
18
C
9
C
1
0
+
+ C
1
1
C
1
2
1
LRCIN
DIN
BCKIN
Audio Serial Data I/F
R
2
2
3
AGND
System Clock Input
5
R
2
SCLK
Notes: 1.
2.
3.
AGND and DGND should be connected as close to the WM8740 as possible.
C
2
to
C
5
,
and C
1
should be positioned as close to the WM8740 as possible.
C
9
1
Capacitor type used can have a big effect on device performance. It is
recommended that Capacitors with very low ESR are used and that ceramics are
either NPO or COG type material to achieve best performance from the WM8740.
Figure 25 External Components Diagram
RECOMMENDED EXTERNAL COMPONENTS VALUES
COMPONENT
REFERENCE
C1 and C6
C2 to C5
C7 and C8
C9 and C11
C10 and C12
R1
R2
SUGGESTED
VALUE
10μF
0.1μF
10μF
0.1μF
10μF
10kΩ
51Ω
Resistor to AVDD for open drain output operation.
Source termination Resistors
DESCRIPTION
De-coupling for DVDD and AVDD.
De-coupling for DVDD and AVDD.
Output AC coupling caps to remove VMID DC level from outputs.
Reference de-coupling Capacitors for VMIDR and VMIDL.
Table 21 External Components Description
w
PD, Rev 4.3, August 2009
24