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WM8776
24-bit, 192kHz Stereo Codec with 5 Channel I/P Multiplexer
WOLFSON MICROELECTRONICS plc
w :: www.wolfsonmicro.com
Product Preview, June 2004, Rev 1.91
Copyright
2004 Wolfson Microelectronics plc
DESCRIPTION
The WM8776 is a high performance, stereo audio codec
with five channel input selector. The WM8776 is ideal for
surround sound processing applications for home hi-fi,
DVD-RW and other audio visual equipment.
A stereo 24-bit multi-bit sigma delta ADC is used with a
five stereo channel input mixer. Each ADC channel has
programmable gain control with automatic level control.
Digital audio output word lengths from 16-32 bits and
sampling rates from 32kHz to 96kHz are supported.
A stereo 24-bit multi-bit sigma delta DAC is used with
digital audio input word lengths from 16-32 bits and
sampling rates from 32kHz to 192kHz. The DAC has an
input mixer allowing an external analogue signal to be
mixed with the DAC signal. There are also Headphone
and line outputs, with volume controls for the
headphones.
The WM8776 supports fully independent sample rates
for the ADC and DAC. The audio data interface supports
I
S, left justified, right justified and DSP formats.
The device is controlled in software via a 2 or 3 wire
serial interface, selected by the MODE pin, which
provides access to all features including channel
selection, volume controls, mutes, and de-emphasis
facilities.
The device is available in a 48-pin TQFP package.
FEATURES
Audio Performance
108dB SNR (‘A’ weighted @ 48kHz) DAC
102dB SNR (‘A’ weighted @ 48kHz) ADC
DAC Sampling Frequency: 32kHz – 192kHz
ADC Sampling Frequency: 32kHz – 96kHz
Five stereo ADC inputs with analogue gain adjust from
+24dB to –21dB in 0.5dB steps
Programmable Limiter or Automatic Level Control (ALC)
Stereo DAC with independent analogue and digital
volume controls
Stereo Headphone and Line Output
3-Wire SPI Compatible or 2-Wire Software Serial
Control Interface
Master or Slave Clocking Mode
Programmable Audio Data Interface Modes
I
2
S, Left, Right Justified or DSP
16/20/24/32 bit Word Lengths
Analogue Bypass Path Feature
Selectable AUX input to the volume controls
2.7V to 5.5V Analogue, 2.7V to 3.6V Digital supply
Operation
APPLICATIONS
BLOCK DIAGRAM
Surround Sound AV Processors and Hi-Fi systems
DVD-RW
HPOUTL
HPOUTR
STEREO
ADC
A
A
V
AUDIO INTERFACE
AND
DIGITAL FILTERS
A
D
D
D
D
STEREO
DAC
AIN2R
AIN3L
AIN4L
AIN4R
AIN5L
AIN5R
AINOPR
AINOPL
AINVGL
AINVGR
A
D
D
V
D
D
CONTROL INTERFACE
A
A
D
C
C
M
D
AIN2L
AIN1R
AIN1L
W
WM8776
A
A
LOW
PASS
FILTERS
A
VOUTL
VOUTR
ALC
I
VMID
HPVDD
HPGND
Z
Z