AD74322 Datasheet, PDF (1/20 Pages) Analog Devices – Low Cost, Low Power Stereo Audio Analog Front End

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Low Cost, Low Power
Stereo Audio Analog Front End
Preliminary Technical Data
AD74322
FEATURES
2.5V Stereo Audio Codec with 3.3 V Tolerant Digital
Interface
FUNCTIONAL BLOCK DIAGRAM
DVDD1(EXT) DVDD2(INT) CLKIN
AVDD
Supports 96 kHz Sample Rates
Supports 16/18 /20/24-Bit Word Lengths
Multibit Sigma Delta Modulators with
“Perfect Differential Linearity Restoration” for
Reduced Idle Tones and Noise Floor
Data Directed Scrambling DACs - Least Sensitive to Jitter
CDIN
CDOUT
CCLK
CLATCH
SPI
Control
Port
Block
ADC
CHANNEL 1
ADC
CHANNEL 2
Performance (20 Hz to 20 kHz)
ASDATA/SDO
90 dB ADC and DAC SNR
DSDATA/SDI
Y Digitally Programmable Input/Output Gain
LRCLK/SDIFS
On-chip Volume Controls Per Output Channel
R _{Hardware and Software Controllable Clickless Mute}
A _{Supports 256xFs, 512xFs and 768xFs Master Mode Clocks}
IN ^{Master Clock Pre-Scaler for use with DSP master clocks}
SDOFS
BCLK/SCLK
L _{Flexible Serial Data Port with Right-Justified, Left-}
IM ^{A Justified, I2S-Compatible and DSP Serial Port Modes}
Supports Packed Data Mode (“TDM”) for cascading
L _{IC devices.}
E _{N On-Chip Reference}
CDIN
R 16, 20 and 24-Lead SOIC, SSOP and TSSOP Package
CDOUT
P ^{H options.}
CCLK
EC ^{TA APPLICATIONS}
T ^{A Digital Video Camcorders (DVC)}
D ^{Portable Audio Devices (Walkman etc)}
CLATCH
ASDATA
I2S
Port
Reference
DGND
REFCAP
DVDD1(EXT) DVDD2(INT) CLKIN
SPI
Control
Port
Block
Audio Processing
Voice Processing
Conference Phones
General Purpose Analog I/O
DSDATA
LRCLK
BCLK
I2S
Port
Reference
DAC
CHANNEL 1
DAC
CHANNEL 2
AGND
AVDD
ADC
CHANNEL 1
ADC
CHANNEL 2
DAC
CHANNEL 1
DAC
CHANNEL 2
VIN1P
VIN1N
VIN2P
VIN2N
VOUT1P
VOUT1N
VOUT2P
VOUT2N
VIN1
VIN2
VOUT1
VOUT2
GENERAL DESCRIPTION
DGND
REFCAP
AGND
The AD74322 is a front-end processor for general purpose
audio and voice applications. It features two multi-bit Σ∆
A/D conversion channels and two multi-bit Σ∆ D/A
DVDD1(EXT) DVDD2(INT) CLKIN
AVDD
conversion channels. Each ADC channel provides >85 dB
signal-to-noise ratio while each DAC channel provides
>90 dB, both over an audio signal bandwidth.
Control
Block
ADC
CHANNEL 1
VIN1
The AD74322 is particularly suitable for a variety of ap-
ADC
plications where stereo input and output channels are
CHANNEL 2
VIN2
required, including audio sections of Digital Video
SDO
Camcorder, portable personal audio devices and the
analog front ends of conference phones . Its high quality
SDI
performance also make it suitable for speech and telephony ^SDIFS
Data
Port
DAC
CHANNEL 1
VOUT1
applications such as speech recognition and synthesis and
SDOFS
modern feature phones.
SCLK
Reference
DAC
CHANNEL 2
VOUT2
DGND
REFCAP
AGND
REV. Pr D 03/00
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
World Wide Web Site: http://www.analog.com
Fax: [phone]
Analog Devices, Inc., 1998