AD1849_15 Datasheet, PDF (1/28 Pages) Analog Devices – Serial-Port 16-Bit SoundPort Stereo Codec

a
Serial-Port 16-Bit
SoundPort^® Stereo Codec
AD1849K
FEATURES
(mono) speaker and stereo headphone drive circuits that require
Single-Chip Integrated ⌺⌬ Digital Audio Stereo Codec
no additional external components. Dynamic range exceeds
Multiple Channels of Stereo Input and Output
80 dB over the 20 kHz audio band. Sample rates from 5.5 kHz
Digital Signal Mixing
to 48 kHz are supported from external crystals, from an external
On-Chip Speaker and Headphone Drive Capability
clock, or from the serial interface bit clock.
Programmable Gain and Attenuation
The Codec includes a stereo pair of Σ∆ analog-to-digital converters
On-Chip Signal Filters
and a stereo pair of Σ∆ digital-to-analog converters. Analog signals
Digital Interpolation and Decimation
Analog Output Low-Pass
Sample Rates from 5.5 kHz to 48 kHz
44-Lead PLCC Package
Operation from 5 V and Mixed 5 V/3.3 V Supplies
Serial Interface Compatible with ADSP-21xx Fixed-
E _{Point DS␮Ps}
Compatible with CS4215 (See Text)
PRODUCT OVERVIEW
T _{The Serial-Port AD1849K SoundPort Stereo Codec integrates}
the key audio data conversion and control functions into a single
integrated circuit. The AD1849K is intended to provide a com-
plete, single-chip audio solution for multimedia applications
E _{requiring operation from a single 5 V supply. External signal}
path circuit requirements are limited to three low tolerance
capacitors for line level applications; anti-imaging filters are
L incorporated on-chip. The AD1849K includes on-chip monaural
can be input at line levels or microphone levels. A software
controlled programmable gain stage allows independent gain for
each channel going into the ADC. The ADCs’ output can be
digitally mixed with the DACs’ input.
The left and right channel 16-bit outputs from the ADCs are
available over a single bidirectional serial interface that also sup-
ports 16-bit digital input to the DACs and control information.
The AD1849K can accept and generate 8-bit µ-law or A-law
companded digital data.
The Σ∆ DACs are preceded by a digital interpolation filter. An
attenuator provides independent user volume control over each
DAC channel. Nyquist images and shaped quantization noise
are removed from the DACs’ analog stereo output by on-chip
switched-capacitor and continuous-time filters. Two independent
stereo pairs of line-level (or one line-level and one headphone)
outputs are generated, as well as drive for a monaural speaker.
ANALOG
O ^SUPPLY
DIGITAL
SUPPLY
FUNCTIONAL BLOCK DIAGRAM
CRYSTALS
22
POWER-DOWN
S ANALOG
IN
LINE L
LINE R
MIC L
MIC R
OB ^{LINE 0 L}
20
dB
LOOPBACK
L
MUX
L
GAIN
R
GAIN
⌺⌬ A/D
CONVERTER
⌺⌬ A/D
CONVERTER
OSCILLATORS
␮/A
LAW
␮/A
LAW
MONITOR MIX
ANALOG
FILTER
ATTENUATE
⌺⌬ D/A
CONVERTER
INTERPOL ATTENUATE
⌺
␮/A
LAW
S
EL
RO
IO
AP
LB
A
PC
OK
R
DIGITAL
I/O
DATA/CONTROL
MODE
DATA/CONTROL
TRANSMIT
ANALOG
LINE 0 R
MUTE
R
L
ANALOG
FILTER
ATTENUATE
⌺⌬ D/A
CONVERTER
INTERPOL ATTENUATE ⌺
␮/A
LAW
T
2
DATA/CONTROL
RECEIVE
PARALLEL I/O
OUT
LINE 1 L
BIT CLOCK
HEADPHONE RETURN
MUTE _R
⌺ MUTE
AD1849K
FRAME SYNC
LINE 1 R
REFERENCE
RESET
OUT
RETURN
MONO SPEAKER
SoundPort is a registered trademark of Analog Devices, Inc.
REV. A
2.25V
CHAINING CHAINING
OUTPUT
INPUT
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., 2000