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24-bit, 192kHz Stereo CODEC
DESCRIPTION
The WM8778 is a high performance, stereo audio
CODEC. It is ideal for surround sound processing
applications for home hi-fi, DVD-RW and other audio
visual equipment.
The stereo 24-bit multi-bit sigma delta ADC has
programmable gain with automatic level control. Digital
audio output word lengths from 16-32 bits and sampling
rates from 32kHz to 96kHz are supported.
A stereo multi-bit sigma delta DAC is used with digital
audio input word lengths from 16-32 bits and sampling
rates from 32kHz to 192kHz. A multiplexor after the DAC
allows the selection of either an external analogue input
or DAC playback into the line outputs.
The WM8778 supports fully independent sample rates
for the ADC and DAC. The audio data interface supports
I
2
S, left justified, right justified and DSP formats.
The device is controlled in software via a 2 or 3 wire
serial interface which provides access to all features
including volume controls, mutes, and de-emphasis
facilities. It can also be controlled in hardware which
gives access to the most commonly used features.
Control interface selection is done via the MODE pin (tri-
level). The device is available in a 28-pin SSOP package.
WM8778
FEATURES
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Audio Performance
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108dB SNR (‘A’ weighted @ 48kHz) DAC
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102dB SNR (‘A’ weighted @ 48kHz) ADC
DAC Sampling Frequency: 32kHz – 192kHz
ADC Sampling Frequency: 32kHz – 96kHz
Stereo ADC input analogue gain adjust from +24dB to –21dB
in 0.5dB steps
ADC digital gain from -21.5dB to -103dB in 0.5dB steps
Programmable Automatic Level Control (ALC) or Limiter on
ADC input.
Stereo DAC with analogue line outputs.
3-Wire SPI Compatible or 2-wire Serial Control Interface
Hardware Control Mode
Master or Slave Clocking Mode
Programmable Audio Data Interface Modes
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•
I
2
S, Left, Right Justified or DSP
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16/20/24/32 bit Word Lengths
Analogue Bypass Path Feature
2.7V to 5.5V Analogue, 2.7V to 3.6V Digital supply Operation
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APPLICATIONS
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•
Surround Sound AV Processors and Hi-Fi systems
DVD-RW
BLOCK DIAGRAM
WOLFSON MICROELECTRONICS plc
w :: www.wolfsonmicro.com
Production Data, April 2005, Rev 4.0
Copyright
2005
Wolfson Microelectronics plc
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
