a Low Cost, Low Power CMOS
General-Purpose Dual Analog Front End
Two 16-Bit A/D Converters
Two 16-Bit D/A Converters
Programmable Input/Output Sample Rates
78 dB ADC SNR
77 dB DAC SNR
64 kS/s Maximum Sample Rate
–90 dB Crosstalk
Low Group Delay (25 s Typ per ADC Channel,
50 s Typ per DAC Channel)
Programmable Input/Output Gain
Flexible Serial Port which Allows Up to Four Dual
Codecs to be Connected in Cascade Giving Eight
Single (+2.7 V to +5.5 V) Supply Operation
73 mW Typ Power Consumption at 3.0 V
28-Lead SOIC and 44-Lead LQFP Packages
General Purpose Analog I/O
Cordless and Personal Communications
Active Control of Sound and Vibration
Wireless Local Loop
The AD73322 is a dual front-end processor for general-purpose
applications including speech and telephony. It features two
16-bit A/D conversion channels and two 16-bit D/A conversion
channels. Each channel provides 77␣ dB signal-to-noise ratio
over a voiceband signal bandwidth. It also features an input-to-
output gain network in both the analog and digital domains.
This is featured on both codecs and can be used for impedance
matching or scaling when interfacing to Subscriber Line Inter-
face Circuits (SLICs).
The AD73322 is particularly suitable for a variety of applica-
tions in the speech and telephony area, including low bit rate,
high quality compression, speech enhancement, recognition, and
synthesis. The low group delay characteristic of the part makes
it suitable for single or multichannel active control applications.
FUNCTIONAL BLOCK DIAGRAM
ADC CHANNEL 1
DAC CHANNEL 1
ADC CHANNEL 2
DAC CHANNEL 2
AGND1 AGND2 DGND
The A/D and D/A conversion channels feature programmable
input/output gains with ranges of 38 dB and 21 dB respectively.
An on-chip reference voltage is included to allow single-supply
operation. This reference is programmable to accommodate
either 3 V or 5 V operation.
The sampling rate of the codecs is programmable with four
separate settings, offering 64 kHz, 32 kHz, 16 kHz and 8 kHz
sampling rates (from a master clock of 16.384 MHz).
A serial port (SPORT) allows easy interfacing of single or cas-
caded devices to industry standard DSP engines. The SPORT
transfer rate is programmable to allow interfacing to both fast
and slow DSP engines.
The AD73322 is available in 28-lead SOIC and 44-lead LQFP
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.
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© Analog Devices, Inc., 2000