AD1843JS Analog Devices Inc, AD1843JS Datasheet - Page 11

• Manufacturer Part Number: AD1843JS
• Description: IC CODEC STEREO 5V 16BIT 80PQFP
• Manufacturer: Analog Devices Inc
• Type: Stereo Audior

Specifications of AD1843JS

• Rohs Status: RoHS non-compliant
• Data Interface: Serial
• Resolution (bits): 16 b
• Number Of Adcs / Dacs: 1 / 2
• Sigma Delta: Yes
• S/n Ratio, Adcs / Dacs (db) Typ: 92 / 86
• Dynamic Range, Adcs / Dacs (db) Typ: 85 / 80
• Voltage - Supply, Analog: 4.75 V ~ 5.25 V
• Voltage - Supply, Digital: 2.85 V ~ 5.25 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 80-MQFP, 80-PQFP

REV. 0
POWER SUPPLIES
Pin Name PQFP
V
GNDA
V
GNDD
NC
(continued from page 1)
The versatility of the device is shown by the following examples
of functions it can perform:
• Stereo audio input and/or quad output, simultaneously at dif-
• Stereo audio output with simultaneous full duplex modem or
• Mono audio input and stereo audio output with simultaneous
• Dual independent audio inputs with audio output for echo-
Audio Functional Description
The AD1843 SoundComm codec provides a complete audio so-
lution with very few external components required. Dynamic
range of the device exceeds 80 dB over the 20 kHz audio band
and sample rates from 4 kHz to 49 kHz are supported (up to
54 kHz for a single channel if other channels are powered
down). The audio functionality of this device is a superset of
that found in the Analog Devices AD1848 SoundPort
which has set the business audio standard throughout the com-
puter industry.
Inputs to the device include a stereo microphone pair, a stereo
line pair, a stereo CD input pair (AUX1), a stereo synthesized
music input pair (AUX2), a dual phone line input (AUX3), a
mono input, and a stereo input from an FM synthesizer (SUM).
All of these inputs (except SUM) are multiplexed to the two
A/D converters and are mixable directly as analog signals with
the outputs of the D/A converters. All analog input signals (ex-
cept SUM) can be amplified, attenuated or muted before mix-
ing with the outputs of the D/A converters.
The device has two pairs of
digital data from the serial port. Each DAC pair’s independent
sampling rate can either be programmed by Control Register
(with 1 Hz resolution) or synchronized to an external input.
The second pair of DACs can be used to replace the music syn-
thesis DAC pair found on many audio products for PCs. Out-
puts from the AD1843 include a line output, a mono output, a
stereo headphone output with its own current return path, and a
SoundPort is a registered trademark of Analog Devices, Inc.
CC
DD
ferent sample rates
fax operation with frequency and phase resampling
modem receive and transmit for simultaneous voice and data
communications
cancelling speakerphones
20, 41, 44
21, 37, 40, 48
4, 8, 50, 53,
63, 64, 68, 72, 79, 80, 85, 90,
77
3, 7, 54, 60,
65, 69, 73, 78
TQFP
25, 51, 55
27, 46, 49, 59 O
5, 10, 62, 66, I
96
4, 9, 67, 75,
81, 86, 91, 97
3, 8, 13, 14,
24, 26, 32, 37,
42, 50, 52, 60,
63, 68, 73, 78,
83, 88, 93, 98
DACs which accept 8- or 16-bit
I/O
I
I
Description
Analog Supply Voltage (+5 V).
Analog Ground.
Digital Supply Voltage (+5/3 V).
Digital Ground.
No Connect. May be left floating.
®
device
–11–
differential stereo output for connection to a DAA. The line and
differential outputs are looped back to the ADC input selector.
The AD1843’s mixing and routing capabilities are extensive.
The digital data from both DAC channels after interpolation
can be routed back to the ADC decimators, to support digital-
to-digital sample rate conversion (digital resampling). Digital
data from the ADC can also be routed to the two stereo DAC
pairs, for a digital loopback mode which is helpful for device-
level and board-level test. Digital data from either stereo DAC
can be mixed with the digital data feeding the other DAC, and
the analog signal from DAC2 can be mixed with the analog out-
put from DAC1.
Sample rates are independently programmable in the range of
4 kHz to 54 kHz to a 1 Hz resolution or sample rates can be
synchronized to an external source. Up to three different signals
can be applied to the device’s three digital phase lock loop
SYNC inputs for external synchronization.
These SYNC inputs can also be used in a special mode for au-
dio/video synchronization. In this mode, an NTSC or PAL de-
rived clock signal (approximately 15 kHz) is applied to the
SYNC inputs and the device produces one of a variety of stan-
dard audio sample rates (32 kHz, 44.056 kHz, 44.1 kHz and
48 kHz, and most of these divided by the integers 1 through 8).
In this manner, video and audio sample rates which are math-
ematically unrelated can be locked together.
Data Communications/Telephony Functional Description
The AD1843 includes all data conversion, filtering, and clock
generation circuitry needed to implement an echo-cancelling
modem with a companion digital signal processor. Software-
programmable sample rates and clocking modes support all
established modem standards including those for the V.34
standard.
The AD1843 utilizes advanced
entire echo-cancelling modem implementation into the digital
domain. The device maintains 90 dB typical dynamic range
throughout all filtering and data conversion across a 9.6 kHz
passband. Purely DSP-based echo cancellation algorithms can
maintain robust bit error rates under worst-case signal attenua-
tion and echo amplitude conditions. The AD1843’s on-chip
interpolation filter resamples (both frequency and phase) the re-
ceived signal after echo cancellation in the DSP, freeing the pro-
cessor for other voice or data communications tasks.
technology to move the
AD1843