a
High Performance Multibit - DAC
with SACD Playback
AD1955
FUNCTIONAL BLOCK DIAGRAM
MASTER
CLOCK INPUT
CONTROL
DATA INPUT
3
DSD
BITSTREAM
INPUT
4
DIGITAL
SUPPLY
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 0.0002 dB
Pass-Band Ripple
8 Oversampling Digital Filter
On-Chip Clickless Volume Control
Supports SACD-Mute Pattern Detection
Supports 64 f
S
/128 f
S
DSD SACD with Phase Mode
Internal Digital Filter Pass-Through for External Filter
Master Clock: 256 f
S
, 512 f
S
, 768 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-
Justified, I
2
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
AUTO-CLOCK
DIVIDER
16-/20-/24-BIT
AUDIO DATA/
EXTERNAL
DIGITAL
FILTER INPUT
3/4
MUX
SPI CONTROL
DSD FILTER
SERIAL DATA
INTERFACE
EXTERNAL
FILTER I/F
RESET
MUTE
DIGITAL
FILTER ENGINE
S/H
ANALOG
SUPPLY
ZERO
FLAGS
NOISE-SHAPED
SCRAMBLING
MULTIBIT -
MODULATOR
I-DAC
I-DAC
VOLTAGE
REFERENCE
L-CH
R-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
(continued on page 12)
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.
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
© Analog Devices, Inc., 2002
AD1955–SPECIFICATIONS
TEST CONDITIONS
(Unless otherwise noted.)
Analog Supply Voltages (AV
DD
) . . . . . . . . . . . . . . . . . . . . 5 V
Digital Supply Voltages (DV
DD
) . . . . . . . . . . . . . . . . . . . . 5 V
Reference Current (I
REF
) . . . . . . . . . . . . . . . . . . . . . 0.960 mA
Ambient Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . 25°C
Input Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.288 MHz
Input Signal . . . . . . . . . . . . . . . . . 984.375 Hz, 0 dB Full Scale
Input Sample Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 kHz
Measurement Bandwidth . . . . . . . . . . . . . . . . 20 Hz to 20 kHz
Word Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Bits
Load Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 pF
Load Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 kΩ
Input Voltage HI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 V
Input Voltage LO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.8 V
ANALOG PERFORMANCE
Parameter
Resolution
(See figures. I
REF
= 0.960 mA, V
BIAS
= 2.80 V.)
Min
Typ
24
120
123
119
120
123
119
–110
8.64
100
–3.24
2.245
2.39
–90
2.505
±
6
0.26
114
Max
Unit
Bits
dB
dB
dB
dB
dB
dB
dB
mA p-p
pF
mA
dB
V
%
dB
ppm/°C
dB
Degrees
dB
dB
SIGNAL-TO-NOISE RATIO (20 Hz to 20 kHz)*
Differential Output (A-Weighted, RMS) (Stereo)
Differential Output (A-Weighted, RMS) (Mono)
Single-Ended (A-Weighted, RMS) (Stereo)
DYNAMIC RANGE (20 Hz to 20 kHz, –60 dB Input)*
Differential Output (A-Weighted, RMS) (Stereo)
Differential Output (A-Weighted, RMS) (Mono)
Single-Ended (A-Weighted, RMS) (Stereo)
Total Harmonic Distortion + Noise (Stereo) at 0 dBFS
ANALOG OUTPUTS
Differential Output Range (Full Scale)
Output Capacitance at Each Output Pin
Output Bias Current, Each Output
Out-of-Band Energy (0.5
Reference Voltage
f
S
to 100 kHz)
114
–102.5
DC ACCURACY
Gain Error
Interchannel Gain Mismatch
Gain Drift
Interchannel Crosstalk (EIAJ Method)
Interchannel Phase Deviation
Mute Attenuation
De-Emphasis Gain Error
0.01
25
–125
±
0.1
–100
±
0.1
*Measured
with Audio Precision System Two Cascade in RMS Mode. Averaging Mode will show approximately 2 dB better performance.
Performance of right and left channels are identical (exclusive of the Interchannel Gain Mismatch and Interchannel Phase Deviation specifications).
Specifications subject to change without notice.
–2–
REV. 0
AD1955
DIGITAL I/O
Parameter
Input Voltage HI (V
IH
)
Input Voltage LO (V
IL
)
Input Leakage (I
IH
@ V
IH
= 2.4 V)
Input Leakage (I
IL
@ V
IL
= 0.8 V)
High Level Output Voltage (V
OH
) I
OH
= 1 mA
Low Level Output Voltage (V
OL
) I
OL
= 1 mA
Input Capacitance
Specifications subject to change without notice.
(–40 C to +85 C, unless otherwise noted.)
Min
2.2
–3
–3
2.4
0.8
+3
+3
0.4
20
Typ
Max
Unit
V
V
µA
µA
V
V
pF
TEMPERATURE
Parameter
Specifications Guaranteed
Functionality Guaranteed
Storage
Specifications subject to change without notice.
Min
–40
–55
Typ
25
Max
+85
+125
Unit
°C
°C
°C
POWER
Parameter
SUPPLIES
Voltage, Digital
Voltage, Analog
Analog Current
Analog Current—Reset
Digital Current
Digital Current—Reset
DISSIPATION
Operation—Both Supplies
Operation—Analog Supply
Operation—Digital Supply
POWER SUPPLY REJECTION RATIO
1 kHz 300 mV p-p Signal at Analog Supply Pins
20 kHz 300 mV p-p Signal at Analog Supply Pins
Specifications subject to change without notice.
Min
4.50
4.50
Typ
5
5
20
20
22
2
210
100
110
–77
–72
Max
5.50
5.50
Unit
V
V
mA
mA
mA
mA
mW
mW
mW
dB
dB
DIGITAL FILTER CHARACTERISTICS
Sample Rate (kHz)
44.1
48
96
192
Pass Band (kHz)
DC–20
DC–21.8
DC–39.95
DC–87.2
Stop Band (kHz)
24.1–328.7
26.23–358.28
56.9–327.65
117–327.65
Stop-Band
Attenuation (dB)
110
110
115
95
Pass-Band Ripple (dB)
±
0.0002
±
0.0002
±
0.0005
0/–0.04 (DC – 21.8 kHz)
0/–0.5 (DC – 65.4 kHz)
0/–1.5 (DC – 87.2 kHz)
Specifications subject to change without notice.
REV. 0
–3–
AD1955
SPECIFICATIONS
(continued)
GROUP DELAY
Chip Mode
INT8
INT4
INT2
Mode
Mode
Mode
Group Delay Calculation
5553/(128 f
S
)
5601/(64 f
S
)
5659/(32 f
S
)
f
S
(kHz)
48
96
192
Group Delay
903.8
911.6
921
Unit
µs
µs
µs
Specifications subject to change without notice.
DIGITAL TIMING
Parameter
t
DMP
t
DML
t
DMH
t
DBH
t
DBL
t
DBP
t
DLS
t
DLH
t
DWH
t
DWL
t
DDS
t
DDH
t
DPHS
t
DSDS
t
DSDH
t
DSKP
t
DSKH
t
DSKL
t
DMP
t
DML
t
DMH
t
CLS
t
CLH
t
CDS
t
CDH
t
RSTL
(Guaranteed over –40 C to +85 C, AVDD = DVDD = 5.0 V
Description
MCLK Period (F
MCLK
= 256 F
LRCLK
)
MCLK LO Pulsewidth (All Modes)
MCLK HI Pulsewidth (All Modes)
BCLK/EF_BCLK High
BCLK/EF_BCLK Low
BCLK/EF_BCLK Period
LRCLK/EF_WCLK Setup
LRCLK Hold (DSP Serial Port Mode Only)
EF_WCLK High
EF_WCLK Low
SDATA/EF_LDATA/EF_RDATA Setup
SDATA/EF_LDATA/EF_RDATA Hold
DSD_PHASE Setup
DSD_DATA Setup
DSD_DATA Hold
DSD_SCLK Period
DSD_SCLK High
DSD_SCLK Low
CCLK Period
CCLK LO Pulsewidth
CCLK HI Pulsewidth
CLATCH Setup
CLATCH Hold
CDATA Setup
CDATA Hold
RST LO Pulsewidth
10%.)
Min
50
0.4
0.4
20
20
60
0
15
20
20
0
20
20
5
5
60
20
20
50
15
10
0
15
0
5
10
t
DMP
t
DMP
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Specifications subject to change without notice.
–4–
REV. 0
AD1955
ABSOLUTE MAXIMUM RATINGS
*
PACKAGE CHARACTERISTICS
Parameter
DV
DD
to DGND
AV
DD
to AGND
Digital Inputs
Analog Outputs
AGND to DGND
Reference Voltage
Soldering
Min
–0.3
–0.3
DGND – 0.3
AGND – 0.3
–0.3
Max
6
6
DV
DD
+ 0.3
AV
DD
+ 0.3
+0.3
(AV
DD
+ 0.3)/2
300
10
Unit
V
V
V
V
V
°C
sec
Package
(Thermal Resistance
[Junction-to-Ambient])
JC
(Thermal Resistance
[Junction-to-Case])
JA
Typ
109.0
39.0
Unit
°C/W
°C/W
*Stresses
greater than those listed under Absolute Maximum Ratings may cause
permanent damage to the device. This is a stress rating only; functional operation
of the device at these or any other conditions above those indicated in the
operational section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
ORDERING GUIDE
Model
AD1955ARS
AD1955ARSRL
EVAL-AD1955EB
Temperature
–40°C to +85°C
–40°C to +85°C
Package Description
28-Lead SSOP
28-Lead SSOP
Evaluation Board
Package Option
*
RS-28
RS-28 on 13" Reels
*RS
= Shrink Small Outline Package
PIN CONFIGURATION
DVDD
1
LRCLK/EF_WCLK
2
BCLK/EF_BCLK
3
SDATA/EF_LDATA
4
EF_RDATA
5
DSD_SCLK
6
DSD_LDATA
7
28
DGND
27
MCLK
26
CCLK
25
CLATCH
24
CDATA
TOP VIEW
22
MUTE
(Not to Scale)
DSD_RDATA
8
21
ZEROL
DSD_PHASE
9
AGND
10
IOUTR+
11
IOUTR–
12
FILTR
13
IREF
14
20
ZEROR
19
AGND
18
IOUTL+
17
IOUTL–
16
FILTB
15
AVDD
AD1955
23
PD/RST
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although the
AD1955 features proprietary ESD protection circuitry, permanent damage may occur on devices
subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended
to avoid performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
REV. 0
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