Stereo, Single Supply
16-, 18- and 20-Bit Sigma-Delta DACs
a
AD1857/AD1858
P RO D UCT O VERVIEW
FEATURES
T he AD1857/AD1858 are complete single-chip stereo digital
audio playback components. T hey each comprise an advanced
digital interpolation filter, a revolutionary “linearity-compensated”
multibit sigma-delta (∑∆) modulator with dither, a jitter-tolerant
DAC, switched capacitor and continuous time analog filters and
analog output drive circuitry. Other features include digital
de-emphasis processing and mute. T he AD1857/AD1858
support continuously variable sample rates with essentially
linear phase response, and support 50/15 µs digital de-emphasis
intended for “Redbook” 44.1 kHz sample frequency playback
from Compact Discs. T he user must provide a master clock that
is synchronous with the left/right clock at 256 or 384 times the
Low Cost, High Perform ance Stereo DACs
128 Tim es Oversam pling Interpolation Filter
Multibit ⌺⌬ Modulator w ith Triangular PDF Dither
Discrete Tim e and Continuous Tim e Analog
Reconstruction Filters
Extrem ely Low Out-of-Band Energy
Buffered Outputs w ith 2 k⍀ Output Load Drive
94 dB Dynam ic Range, –90 dB THD+N Perform ance
Digital De-em phasis and Mute
؎0.1؇C Maxim um Phase Linearity Deviation
Continuously Variable Sam ple Rate Support
Pow er-Dow n Mode
16-, 18- and 20-Bit I2S-J ustified, Left-J ustified Modes
Offered on AD1857
intended sample frequency.
T he AD1857/AD1858 have a simple but very flexible serial data
input port that allows for glueless interconnection to a variety of
ADCs, DSP chips, AES/EBU receivers and sample rate con-
verters. T he AD1857 serial data input port can be configured
in either 16-bit, 18-bit or 20-bit left-justified or I2S-justified
modes. T he AD1858 serial data input port can be configured in
either 16-bit right-justified or DSP serial port compatible modes.
T he AD1857/AD1858 accept serial audio data in MSB first,
twos-complement format. A power-down mode is offered to
minimize power consumption when the device is inactive. T he
AD1857/AD1858 operate from a single +5 V power supply.
T hey are fabricated on a single monolithic integrated circuit and
housed in 20-pin SSOP packages for operation over the
temperature range 0°C to +70°C.
Accepts 24-Bit Word
16-Bit Right-J ustified and DSP Serial Port Modes
Offered on AD1858
Single +5 V Supply
20-Pin SSOP Package
APPLICATIONS
Digital Cable TV and Direct Broadcast Satellite Set-Top
Decoder Boxes
Video Laser Disk, Video CD and CD-I Players
High Definition Televisions, Digital Audio Broadcast
Receivers
CD, CD-R, DAT, DCC and MD Players
Digital Audio Workstations, Com puter Multim edia
Products
FUNCTIO NAL BLO CK D IAGRAM
CLOCK
IN
CLOCK
MODE
DIGITAL
SUPPLY
COMMON
MODE
2
16-/18-/20-BIT
3
DIGITAL
SERIAL DATA
INTERFACE
VOLTAGE
REFERENCE
CLOCK
CIRCUIT
DATA INPUT
AD1857/AD1858
128x
INTERPOLATION
FILTER
MULTIBIT
Σ∆ MODULATOR
OUTPUT
BUFFER
ANALOG
FILTER
DAC
MUTE
SERIAL
MODE
ANALOG
OUTPUTS
128x
INTERPOLATION
FILTER
ANALOG
FILTER
MULTIBIT
Σ∆ MODULATOR
OUTPUT
BUFFER
DAC
MUTE
4
DE-EMPHASIS
MUTE
ANALOG
SUPPLY
POWER-DOWN/RESET
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
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© Analog Devices, Inc., 1997