AD1843_15 Datasheet, PDF (1/64 Pages) Analog Devices – Serial-Port 16-Bit SoundComm Codec

a
Serial-Port 16-Bit
SoundComm Codec
AD1843
FEATURES
GENERAL PRODUCT DESCRIPTION
Single Chip Integrated Speech, Audio, Fax and Modem _{The AD1843 SoundComm™ Codec is a complete analog front}
Codec
end for high performance DSP-based telephony and audio ap-
Highly Configurable Stereo ∑∆ ADCs and Quad ∑∆ DACs _{plications. The device integrates the real-world analog I/O re-}
Supports V.34, V.32bis, and Fallback Modem Standards _{quirements for many popular functions thereby reducing size,}
As Well As Voice Over Data
power consumption, and system complexity. The AD1843
Dual Digital Resamplers with Programmable Input and _{SoundComm is the world’s first codec which can support four}
Output Phase and Frequency
Three On-Chip Phase Lock Loops for Synchronization to
External Signals, Including Video
Thirteen Analog Inputs and Seven Analog Outputs
Advanced Analog and Digital Signal Mixing and Digital-
to-Digital Sample Rate Conversion
E _{Programmable Gain, Attenuation and Mute}
On-Chip Signal Filters
Digital Interpolation and Decimation
T ^{Analog Output Low Pass}
1 Hz Resolution Programmable Sample Rates from 4 kHz
to 54 kHz Derived from a Single Clock Input
80-Lead PQFP and 100-Lead TQFP Packages
E ^{Operation from +5 V or Mixed +5 V/+3 V Supplies}
FIFO-Buffered Serial Digital Interface Compatible with
ADSP-21xx Fixed-Point DSPs
Advanced Power Management
L VHDL Model of Serial Port Available; Evaluation Board
and MAFE Board Available
different sample rates simultaneously, without any beat fre-
quency noise issues. This is essential for highly integrated audio/
modem/fax products since the sample rates associated with au-
dio are very much distinct from the sample rates associated with
telephony-oriented data communication. It is also the first codec
to offer on-chip digital phase lock loops for sample rate synchro-
nization to external clock signals. This sample rate flexibility is
enabled through Analog Devices’ Continuous Time Oversampling
(CTO) technology.
The main elements of the AD1843 are its extensive input and mix-
ing section, its two channels of sigma-delta (∑∆) analog-to-digital
conversion, its four channels of ∑∆ digital-to-analog conversion, its
digital filters, and the clock and control circuitry for implementing
the device’s different modes. The AD1843 permits flexible sample-
rate selection through programming and external synchronization,
many input and output options, and many mixing options.
(continued on page 11)
SoundComm is a trademark of Analog Devices, Inc.
SIMPLIFIED FUNCTIONAL BLOCK DIAGRAM
SYNC XTAL CONV BIT
O _{LIN 4}
MIC ²
S AUX1 2
2
AUX2
2
AUX3
1
MIN
B _MOUT
2
O ^LOUT1
MUTE
MUTE
3
2
3
3
20 dB
AD1843
S
CLOCK GENERATION
E
CONTROL
L
E
C
PGA
∑∆
ADC
S
E
T
L
O
S
E
R
E
C
L
T
E
O
C
R
T
GAM GAM GAM GAM GAM
O
R
ATTN
MUTE
REGISTERS
µ/A
LAW
ADC
D
I
G
I
T
A
∑
∑
∑
∑
∑
GAM
∑∆
DAC
LEFT AND
M
∑
U
T
ATTN ∑
E
FIFO
µ/A
LAW
L
DAC1
I
CLKOUT
SCLK
SDFS
SDI
SDO
BM
CS
TSO
DRIVER
RIGHT CHANNELS
MUTE
N
MUTE
GAM
ATTN
T
TSI
E
2
HPOUTL
HPOUTC
MUTE
GAM = GAIN
ATTENUATION
MUTE
MUTE
MUTE
R
XCTL [1:0]
F
A
PDMNFT
C
HPOUTR ₄
LOUT2
SUM
2
LEFT AND
RIGHT CHANNELS
GAM
VOLTAGE REFERENCE
∑∆
DAC
M
∑
U
T
ATTN
E
E
∑
FIFO
µ/A
LAW
DAC2
RESET
PWRDWN
4
3
8
9
REV. 0
V_{REF CMOUT}
AAFILTL AAFILTR
FILTL FILTR
GNDA V_CC
GNDD VDD
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.
© Analog Devices, Inc., 1996
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
Fax: [phone]