危鈭?/div>
DAC
with SACD Playback
Preliminary Technical Data
APPLICATIONS
5V Power Supply Stereo Audio DAC System.
Accepts 16/18/20/24-Bit Data
Supports 24-Bits, 192kHz Sample Rate PCM Audio Data
Supports SACD bit-stream and External Digital Filter Interface
Accepts a Wide Range of PCM Sample Rates Including:
32kHz, 44.1kHz. 48kHz, 88.2kHz, 96kHz, and 192kHz
Multibit Sigma Delta Modulator with 鈥淧erfect Differential
Linearity Restoration鈥?for Reduced Idle Tones and Noise Floor
Data Directed Scrambling DAC - Least Sensitive to Jitter
Supports SACD playback with 鈥淏it Expansion鈥?filter
Differential Current Output for Optimum Performance
8.64 mA p-p Output Current with +3dB headroom in SACD mode
120 dB SNR/DNR (not muted) at 48KHz Sample Rate
(A-Weighted Stereo)
123 dB SNR/DNR (Mono)
-110 dB THD+N
110 dB Stopband Attenuation with +/-0.0002dB Passband Ripple
8 Times Oversampling Digital Filter
On-chip Clickless Volume Control
Supports SACD-Mute pattern detection
Supports 64fs/128fs DSD SACD with phase modulation
Internal Digital Filter pass-through for External Filter
Master clock: 256fs,384fs,512fs,768fs
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, 44.1, 48 KHz Sample Rates
Flexible Serial Data Port with Right-Justified, Left-Justified,
I
2
S-Compatible and DSP Serial Port
28 Lead SSOP Plastic Package
AD1955
High-End DVD-Audio, SACD, CD, Home Theatre Systems, Automotive
Audio Systems, Sampling Musical Keyboards, Digital Mixing
Consoles, Digital Audio Effects Processors
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 DAC section. Other features include an
on-chip clickless stereo attenuator, mute capability, programmed through
an SPI-compatible serial control port. The AD1955 is fully compatible
with all known DVD audio formats including 192kHz as well as 96kHz
sample frequencies and 24-bits. It also is backwards compatible by
supporting 50/15碌s digital de-emphasis intended for 鈥渞edbook鈥?Compact
Discs, as well as de-emphasis at 32kHz and 48kHz sample rate.
The AD1955 has a very flexible serial data input port that allows for
glueless interconnection to a variety of ADCs, DSPs, SACD decoder,
external digital filter, AES/EBU receivers and sample rate converters.
The AD1955 can be configured in Left-justified, I
2
S, Right-Justified, or
DSP serial port compatible modes. It can support MSB first, twos-
compliment format, 16, 18, 20 and 24 bits in all standard PCM modes.
Also the AD1955 has an interface for SACD playback and an external
digital filter interface for use with an external digital interpolation filter
or HDCD decoder. The AD1955 uses a +5 V power supply. It is
fabricated on a single monolithic integrated circuit and is housed in a 28-
pin SSOP package for operation over the temperature range -40
0
C to
+105
0
C.
FUNCTIONAL BLOCK DIAGRAM
Master Clock
Input
Control Data
Input
3
SPI
Control
Digital
Filter
Engine
Multibit
Sigma-Delta
Modulator
Digital
Supply
Auto-Clock
Divider
16/20/24Bit
Audio Data /
External Digital
Filter Input
3/4
Serial Data
Interface
External
Filter I/F
DSD
Filter
Voltage
Reference
I-DAC
L-ch
Differential
Current Output
I-DAC
R-ch
M
U
X
S/H
Noise-
Shaped
Scrambling
DSD
Bitstream
Input
4
RESET
MUTE
Analog
Supply
ZERO Flags
Rev. PrF 3/18/2002
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: 781/329-4700
www.analog.com
Fax: 781/326-8703
漏Analog Devices, Inc., 2002
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