Parallel-Port 16-Bit
SoundPort Stereo Codec
a
AD1848K
supply. It provides a direct, byte-wide interface to both ISA
(“AT ”) and EISA computer buses for simplified implementa-
tion on a computer motherboard or add-in card. T he AD1848K
generates enable and direction controls for IC buffers such as
74_245.
FEATURES
Single-Chip Integrated ∑∆ Digital Audio Stereo Codec
Supports the Microsoft Window s Sound System ®
Multiple Channels of Stereo Input
Analog and Digital Signal Mixing
Program m able Gain and Attenuation
On-Chip Signal Filters
T he AD1848K SoundPort Stereo Codec supports a DMA re-
quest/grant architecture for transferring data with the host com-
puter bus. One or two DMA channels can be supported.
Programmed I/O (PIO) mode is also supported for control
register accesses and for applications lacking DMA control. T wo
input control lines support mixed direct and indirect addressing
of twenty-one internal control registers over this asynchronous
interface.
Digital Interpolation
Analog Output Low -Pass
Sam ple Rates from 5.5 kHz to 48 kHz
68-Lead PLCC and 68-Lead TQFP Packages
Operation from +5 V Supplies
Byte-Wide Parallel Interface to ISA and EISA Buses
Supports One or Tw o DMA Channels and
Program m ed I/ O
External circuit requirements are limited to a minimal number
of low cost support components. Anti-imaging DAC output fil-
ters are incorporated on-chip. Dynamic range exceeds 80 dB
over the 20 kHz audio band. Sample rates from 5.5 kHz to
48 kHz are supported from external crystals.
P RO D UCT O VERVIEW
T he Parallel-Port AD1848K SoundPort® Stereo Codec inte-
grates the key audio data conversion and control functions into
a single integrated circuit. T he AD1848K is intended to provide
a complete, single-chip audio solution for business audio and
multimedia applications requiring operation from a single +5 V
T he Codec includes a stereo pair of ∑∆ analog-to-digital
converters and a stereo pair of ∑∆ digital-to-analog converters.
Inputs to the ADC can be selected from four stereo pairs of
SoundPort is a registered trademark of Analog Devices, Inc.
(Continued on page 9)
FUNCTIO NAL BLO CK D IAGRAM
DIGITAL
SUPPLY
ANALOG
SUPPLY
CRYSTALS
POWER DOWN
2
2
ANALOG
DIGITAL
L_LINE
R_LINE
OSCILLATORS
L
PLAYBACK REQ
PLAYBACK ACK
CAPTURE REQ
16
16
∑∆ A/D
µ/
A
L
A
W
GAIN
GAIN
CONVERTER
20
dB
L_MIC
R_MIC
P
A
R
A
L
L
E
L
MUX
R
∑∆ A/D
CONVERTER
L_AUX1
R_AUX1
CAPTURE ACK
2
ADR1:0
DATA7:0
CS
DIGITAL
MIX
8
GAIN/ATTEN/MUTE
L
P
∑∆ D/A
CONVERTER
O
R
T
ATTEN/
ANALOG
FILTER
µ/
A
L
∑
L_OUT
R_OUT
∑
INTERPOL
ATTENUATE
ATTENUATE
WR
RD
MUTE
R
A
W
BUS DRIVER
CONTROL
2
∑∆ D/A
CONVERTER
ATTEN/
MUTE
ANALOG
FILTER
∑
INTERPOL
∑
HOST DMA
INTERRUPT
L_AUX2
R_AUX2
CONTROL
REGS
REFERENCE
2.25V
GAIN/ATTEN/MUTE
2
EXTERNAL
CONTROL
REV. 0
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norw ood, MA 02062-9106, U.S.A.
Tel: 617/ 329-4700 Fax: 617/ 326-8703