WM8725CGED/R Ver la hoja de datos (PDF) - Wolfson Microelectronics plc
Número de pieza
componentes Descripción
Fabricante
WM8725CGED/R Datasheet PDF : 15 Pages
| |||
WM8725
RECOMMENDED EXTERNAL COMPONENTS
FROM AUDIO
PROCESSOR
ANALOGUE
OUTPUT
FOR RIGHT
CHANNEL
10µF
+
External
LPF
1 LRCIN
SCKI 14
2 DIN
FORMAT 13
3 BCKIN
DEEMPH 12
4 NC WM8725 NC 11
5 CAP
MUTE 10
6 VOUTR
VOUTL 9
7 GND
VDD 8
Production Data
256fs/384fs CLK
External
LPF
ANALOGUE
OUTPUT FOR
LEFT
CHANNEL
GND
10µF
0.1µF
VDD
Figure 7 Recommended External Components
DETAIL OF RECOMMENDED EXTERNAL COMPONENTS SHOWING THE EXTERNAL
LOW PASS FILTER
External LPF
x2 for Stereo Operation
VOUTR
VOUTL
10k
10k
680pF
1500pF
10k
-
+
100pF
Filtered
Analogue
Output
PCB LAYOUT
Figure 8 Third-Order Low Pass Filter (LPF) Example
An external low pass filter is recommended (see Figure 8) if the device is driving a wideband
amplifier. In some applications, second-order or passive RC filter may be adequate.
1. Place all supply decoupling capacitors as close as possible to their respective supply
pins and provide a low impedance path from the capacitors to the appropriate ground.
2. Separate analogue and digital ground planes should be situated under respective
analogue and digital device pins.
3. Avoid noise on the CAP reference pin. The decoupling capacitor should be placed as
close to this pin as possible with a low impedance path from the capacitor to analogue
ground.
4. Digital input signals should be screened from each other and from other sources of
noise to avoid cross-talk and interference. They should also run over the digital ground
plane to avoid introducing unwanted noise into the analogue ground plane.
5. Analogue output signal tracks should be kept as short as possible and over the
analogue ground plane reducing the possibility of losing signal quality.
w
PD ,Rev 4.3, February 2012
11
Share Link: 