WM8740
Production Data
RECOMMENDED EXTERNAL COMPONENTS
DVDD
8
AVDD
15
9
DVDD
DGND
AVDD
+
C1
C2
AVDDR
AVDDL
7
20
+
C3
C4
C5
C6
DGND
14
10
19
16
17
AGND
AGNDR
AGNDL
AGND
28
27
26
23
22
-
ML/I2S
VOUTLN
VOUTLP
LEFT OUTPUT DATA
+
MC/DM1
MD/DM0
CSB/IWO
RSTB
Software I/F or
Hardware Control
13
12
-
VOUTRN
VOUTRP
RIGHT OUTPUT DATA
+
12
6
MODE8X
WM8740
AVDD
DIFFHW
MODE
R1
24
25
21
ZERO
11
18
MUTEB
VMIDR
VMIDL
+
C
C12
+
11
1
2
3
LRCIN
DIN
C9
C10
Audio Serial Data I/F
System Clock Input
BCKIN
AGND
R2
R2
5
SCLK
Notes: 1. AGND and DGND should be connected as close to the WM8740 as possible.
2. 2 to C5, C9 and C11 should be positioned as close to the WM8740 as possible.
C
3. 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 21 External Components Diagram
RECOMMENDED EXTERNAL COMPONENTS VALUES
COMPONENT
REFERENCE
SUGGESTED
VALUE
DESCRIPTION
C1 and C6
C2 to C5
C7 and C8
C9 and C11
C10 and C12
R1
10µF
0.1µF
10µF
0.1µF
10µF
10kΩ
51Ω
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.
Resistor to AVDD for open drain output operation.
Source termination resistors.
R2
Table 21 External Components Description
PD Rev 4.0 April 2004
21
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
