AD1843 Datasheet, PDF (1/64 Pages) Analog Devices – Serial-Port 16-Bit SoundComm Codec

a
Serial-Port 16-Bit
SoundComm Codec
AD1843
FEATURES
Single Chip Integrated Speech, Audio, Fax and Modem
Codec
Highly Configurable Stereo ∑∆ ADCs and Quad ∑∆ DACs
Supports V.34, V.32bis, and Fallback Modem Standards
As Well As Voice Over Data
Dual Digital Resamplers with Programmable Input and
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
Programmable Gain, Attenuation and Mute
On-Chip Signal Filters
Digital Interpolation and Decimation
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
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
VHDL Model of Serial Port Available; Evaluation Board
and MAFE Board Available
GENERAL PRODUCT DESCRIPTION
The AD1843 SoundComm™ Codec is a complete analog front
end for high performance DSP-based telephony and audio ap-
plications. The device integrates the real-world analog I/O re-
quirements for many popular functions thereby reducing size,
power consumption, and system complexity. The AD1843
SoundComm is the world’s first codec which can support four
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
LIN ⁴
MIC ²
AUX1 ²
2
AUX2
2
AUX3
1
MIN
MOUT
2
LOUT1
HPOUTL
HPOUTC
HPOUTR ₄
LOUT2
SUM
2
3
2
3
3
20 dB
AD1843
S
CLOCK GENERATION
CLKOUT
E
CONTROL
MUTE
MUTE
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
∑
∑
∑
∑
∑
GAM
∑∆
DAC
LEFT AND
M
∑
U
T
ATTN ∑
E
REGISTERS
µ/A
LAW
FIFO
µ/A
LAW
ADC
D
I
G
I
T
A
L
DAC1
I
SCLK
SDFS
SDI
SDO
BM
CS
TSO
DRIVER
RIGHT CHANNELS
MUTE
GAM
MUTE
ATTN
N
T
TSI
E
2
MUTE
GAM = GAIN
ATTENUATION
MUTE
MUTE
MUTE
R
XCTL [1:0]
F
A
PDMNFT
C
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]