Harman Kardon HK 990/230 Service Manual page 9

a
FEATURES
5 V Power Supply Stereo Audio DAC System
Accepts 16-/18-/20-/24-Bit Data
Supports 24-Bit, 192 kHz Sample Rate PCM Audio Data
Supports SACD Bit Stream and External Digital Filter
Interface
Accepts a Wide Range of PCM Sample Rates Including:
32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, and
192 kHz
Multibit Sigma-Delta Modulator with "Perfect Differen-
tial Linearity Restoration" for Reduced Idle Tones and
Noise Floor
Data Directed Scrambling DAC––Low Sensitivity to Jitter
Supports SACD Playback with "Bit Expansion" Filter
Differential Current Output for Optimum Performance
8.64 mA p-p Differential Output
120 dB SNR/DNR (not muted) at 48 kHz Sample Rate
(A-Weighted Stereo)
123 dB SNR/DNR (Mono)
–110 dB THD + N
110 dB Stop-Band Attenuation with
Pass-Band Ripple
8 Oversampling Digital Filter
On-Chip Clickless Volume Control
Supports SACD-Mute Pattern Detection
Supports 64 f /128 f DSD SACD with Phase Mode
S S
Internal Digital Filter Pass-Through for External Filter
Master Clock: 256 f , 512 f
S
Hardware and Software Controllable Clickless Mute
Serial (SPI) Control for Serial Mode, Number of Bits,
Sample Rate, Volume, Mute, De-Emphasis, Mono Mode
Digital De-Emphasis for 32 kHz, 44.1 kHz, and 48 kHz
Sample Rates
Flexible Serial Data Port with Right-Justified, Left-
2
Justified, I S, and DSP Modes
28-Lead SSOP Plastic Package
APPLICATIONS
High End DVD Audio
SACD
CD
Home Theater Systems
Automotive Audio Systems
Sampling Musical Keyboards
Digital Mixing Consoles
Digital Audio Effects Processors
REV. 0
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 that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
High Performance Multibit - DAC
0.0002 dB
, 768 f
S S
FUNCTIONAL BLOCK DIAGRAM
MASTER
CLOCK INPUT
AUTO-CLOCK
DIVIDER
16-/20-/24-BIT
3/4
AUDIO DATA/
EXTERNAL
DIGITAL
FILTER INPUT
SERIAL DATA
INTERFACE
DIGITAL
FILTER ENGINE
NOISE-SHAPED
SCRAMBLING
I-DAC
L-CH
DIFFERENTIAL
CURRENT OUTPUT
PRODUCT OVERVIEW
The AD1955 is a complete, high performance, single-chip, stereo
digital audio playback system. It is comprised of a multibit sigma-
delta modulator, high performance digital interpolation filters,
and continuous-time differential current output DACs. Other
features include an on-chip clickless stereo attenuator and mute
capability, programmed through an SPI compatible serial control
port. The AD1955 is fully compatible with all known DVD audio
formats including 192 kHz as well as 96 kHz sample frequencies
and 24 bits. It is also backward compatible by supporting 50 µs/
15 µs digital de-emphasis intended for "redbook" compact discs,
as well as de-emphasis at 32 kHz and 48 kHz sample rates.
The AD1955 has a very flexible serial data input port that
allows for glueless interconnection to a variety of ADCs, DSPs,
SACD decoders, external digital filters, AES/EBU receivers, and
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
Fax: 781/326-8703
7
with SACD Playback
AD1955ARS
DSD
CONTROL BITSTREAM
DATA INPUT
INPUT
3 4
SPI CONTROL
MUX DSD FILTER
EXTERNAL
FILTER I/F
S/H
MULTIBIT -
MODULATOR
VOLTAGE
REFERENCE
I-DAC
R-CH
(continued on page 12)
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© Analog Devices, Inc., 2002
DIGITAL
SUPPLY
RESET
MUTE
ANALOG
SUPPLY
ZERO
FLAGS