WM8774
24-bit, 192kHz 8-Channel Input Stereo Codec
DESCRIPTION
The WM8774 is a high performance, stereo audio codec
with an 8 channel input selector. The WM8774 is ideal 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 an
eight stereo channel input selector. Each channel has
analogue domain mute and programmable gain control.
Digital audio output word lengths from 16-32 bits and
sampling rates from 8kHz to 96kHz are supported.
A stereo 24-bit multi-bit sigma delta DAC is used with
oversampling digital interpolation filters. Digital audio input
word lengths from 16-32 bits and sampling rates from 8kHz
to 192kHz are supported. Each DAC channel has
independent analogue volume and mute control, with a set
of input multiplexors allowing selection of an external
analogue input into these volume controls.
The audio data interface supports I
2
S, left justified, right
justified and DSP digital audio formats.
The device is controlled via a 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 64-pin
TQFP package.
FEATURES
•
Audio Performance
−
106dB SNR (‘A’ weighted @ 48kHz) DAC
−
101dB SNR (‘A’ weighted @ 48kHz) ADC
DAC Sampling Frequency: 8kHz – 192kHz
ADC Sampling Frequency: 8kHz – 96kHz
3-Wire SPI Compatible 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
Stereo DAC with independent analogue and digital volume
controls
Analogue Bypass Path Feature
Selectable AUX input to the volume controls
Eight stereo ADC inputs with analogue gain adjust from
+19dB to –12dB in 1dB steps
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
DACREFN2
DACREFP1
VMIDDAC
BLOCK DIAGRAM
VMIDADC
REFADC
AINVGR
ZFLAGR
ZFLAGL
AINVGL
AGND
AVDD
MCLK
DOUT
ADCLRC
BCLK
DACLRC
DIN
AGND2
AIN1L
AIN1R
AIN2L
AIN2R
AIN3L
AIN3R
AIN4L
AIN4R
AIN5L
AIN5R
AIN6L
AIN6R
AIN7L
AIN7R
AIN8L
AIN8R
INPUT SOURCE SELECTOR
AUDIO INTERFACE
STEREO
ADC
AND
DIGITAL FILTERS
STEREO
DAC
LOW
PASS
FILTERS
AVDD2
VOUTL
VOUTR
AINOPL
AINOPR
RECL
RECR
MUTE
CONTROL INTERFACE
WM8774
GR1
GR2
AUXL
AUXR
CL
RESETB
DGND
WOLFSON MICROELECTRONICS LTD
w :: www.wolfsonmicro.com
DVDD
CE
DI
Product Preview, June 2002, Rev 1.0
Copyright
2002
Wolfson Microelectronics Ltd.
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
