WM8728
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RECOMMENDED DSD EXTERNAL COMPONENTS
DVDD
AVDD
+
7
6
10
14
DVDD
DGND
AVDD
+
C1
C2
VREFP
C3
C4
C5
9
AGND
DGND
DVDD
13
VREFN
AGND
15
20
19
18
17
CSBIWL
LATI2S
SCKDSD
SDIDEM
MUTEB
MUTE Control
C6
8
VOUTR
VOUTL
AC-Coupled
VOUTR/L
to External LPF
16
MODE
WM8728
C7
11
DGND
1
4
DSD right bitstream
DSD bit clock
LRCIN
MCLK
3
2
BCKIN
DIN
DSD biphase mode clock
DSD left bitstream
5
12
ZERO
VMID
+
C8
C9
AGND
Notes:
1. AGND and DGND should be connected as close to the WM8728 as possible.
2. C2, C3, C4 and C8 should be positioned as close to the WM8728 as possible.
3. Capacitor types should be carefully chosen. Capacitors with very low ESR are
recommended for optimum performance.
4. When using monophase DSD encoding pin 3 BCKIN should be tied to
DVDD. In Biphase DSD encoding BCKIN runs at 2 cycles per bit.
Figure 31 External Connections for DSD Applications
RECOMMENDED EXTERNAL COMPONENTS VALUES FOR DSD
COMPONENT
REFERENCE
SUGGESTED
VALUE
DESCRIPTION
C1 and C5
C2 to C4
C6 and C7
C8
10µF
0.1µF
10µF
0.1µF
10µF
De-coupling for DVDD and AVDD.
De-coupling for DVDD and AVDD.
Output AC coupling caps to remove midrail DC level from outputs.
Reference de-coupling capacitors for VMID pin.
C9
Table 23 External Components for DSD
WOLFSON MICROELECTRONICS LTD
PP Rev 1.2 April 2001
26
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
