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DESCRIPTION
The WM8775 is a high performance, stereo audio ADC
with a 4 channel input mixer. The WM8775 is ideal for
digitising multiple analogue sources for surround sound
processing applications for home hi-fi, automotive and
other audio visual equipment.
A stereo 24-bit multi-bit sigma delta ADC is used with a
four stereo channel input selector. Each channel has
programmable gain control. Digital audio output word
lengths from 16-32 bits and sampling rates from 32kHz
to 96kHz are supported.
The audio data interface supports I S, left justified, right
justified and DSP digital audio formats.
The device is controlled via a 2 or 3 wire serial interface.
The interface provides access to all features including
channel selection, volume controls, mutes, de-emphasis
and power management facilities.
The device is available in a 28-pin SSOP package. The
WM8775 is software compatible with the WM8776.
2
WM8775
24-bit, 96kHz ADC with 4 Channel I/P Multiplexer
FEATURES
•
Audio Performance
−
102dB SNR (‘A’ weighted @ 48kHz)
−
-90dB THD
ADC Sampling Frequency: 32kHz – 96kHz
Four stereo ADC inputs with analogue gain adjust from
+24dB to –21dB in 0.5dB steps
Digital gain adjust from -21.5dB to -103dB.
Programmable Automatic Level Control (ALC) or Limiter on
ADC input
3-Wire SPI Compatible or 2-wire 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
2.7V to 5.5V Analogue, 2.7V to 3.6V Digital supply Operation
5V tolerant digital inputs
•
•
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APPLICATIONS
•
•
Surround Sound AV Processors and Hi-Fi systems
Automotive Audio
BLOCK DIAGRAM
ADCREFGND
ADCREFP
VMIDADC
AGND
AVDD
AINOPL
AINOPR
AINVGL
AINVGR
W
WM8775
AIN1L
AIN1R
AIN2L
AIN2R
AIN3L
AIN3R
AIN4L
AIN4R
INPUT MIXER
AUDIO INTERFACE
STEREO
ADC
VMID
ALC
AND
DIGITAL FILTERS
MCLK
DOUT
ADCLRC
BCLK
CONTROL INTERFACE
MODE
CE
WOLFSON MICROELECTRONICS plc
w :: www.wolfsonmicro.com
DGND
DVDD
CL
DI
Product Preview, June 2004, Rev 1.8
Copyright
2004
Wolfson Microelectronics plc
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
