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Электронный компонент: AD1819

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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.
a
AD1819B
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
Analog Devices, Inc., 1999
AC'97 SoundPort
Codec
AC'97 FEATURES
Fully Compliant AC'97 Analog I/O Component
48-Terminal LQFP Package
Multibit
Converter Architecture for Improved
S/N Ratio >90 dB
16-Bit Stereo Full-Duplex Codec
Four Analog Line-Level Stereo Inputs for Connection
from LINE, CD, VIDEO, and AUX
Two Analog Line-Level Mono Inputs for Speakerphone
and PC BEEP
Mono MIC Input Switchable from Two External
Sources
High Quality CD Input with Ground Sense
Stereo Line Level Output
Mono Output for Speakerphone
Power Management Support
ENHANCED FEATURES
Support for Multiple Codec Communications
DSP 16-Bit Serial Port Format
Variable 7 kHz to 48 kHz Sampling Rate with 1 Hz
Resolution
Supports Modem Sample Rates and Filtering
PhatTM Stereo 3D Stereo Enhancement
VHDL and Verilog Models of Serial Port Available
SoundPort is a registered trademark of Analog Devices, Inc.
Phat is a trademark of Analog Devices, Inc.
FUNCTIONAL BLOCK DIAGRAM
G
A
M
G
A
M
G
A
M
AC LINK
SYNC
BIT_CLK
PHAT
STEREO
PHAT
STEREO
G
A
M
A
M
MV
0dB/
20dB
MV
AD1819B
MIC1
MIC2
AUX
CD
VIDEO
PC_BEEP
LINE_OUT_L
MONO_OUT
LINE_IN
PHONE_IN
LINE_OUT_R
MV
SELECTOR
PGA
PGA
16-BIT
A/D
CONVERTER
G
A
M
SAMPLE
RATE
GENERATORS
G = GAIN
A = ATTENUATE
M = MUTE
MV = MASTER VOLUME
OSCILLATORS
XTALO
XTALI
CS1 CHAIN_IN
CHAIN_CLK
RESET
SDATA_IN
CS0
MASTER/SLAVE
SYNCHRONIZER
SDATA_OUT
G
A
M
16-BIT
A/D
CONVERTER
G
A
M
G
A
M
16-BIT
D/A
CONVERTER
16-BIT
D/A
CONVERTER
AD1819B
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PRODUCT OVERVIEW
The AD1819B SoundPort Codec is designed to meet all require-
ments of the Audio Codec '97, Component Specification, Revision
1.03, 1996, Intel Corporation, found at www.Intel.com. In
addition, the AD1819B supports multiple codec configurations
(up to three per AC-Link), a DSP serial mode, variable sample
rates, modem sample rates and filtering, and built-in Phat Ste-
reo 3D enhancement.
The AD1819B is an analog front end for high performance PC
audio, modem, or DSP applications. The AC'97 architecture
defines a 2-chip audio solution comprising a digital audio con-
troller, plus a high quality analog component that includes
Digital-to-Analog Converters (DACs), Analog-to-Digital Con-
verters (ADCs) mixer and I/O.
The main architectural features of the AD1819B are the high
quality analog mixer section, two channels of
ADC conver-
sion, two channels of
DAC conversion and Data Direct
Scrambling (D
2
S) rate generators. The AD1819B's left channel
ADC and DAC are compatible for modem applications support-
ing irrational sample rates and modem filtering requirements.
FUNCTIONAL DESCRIPTION
This section overviews the functionality of the AD1819B and is
intended as a general introduction to the capabilities of the
device. Detailed reference information may be found in the
descriptions of the Indexed Control Registers.
Analog Inputs
The codec contains a stereo pair of
ADCs. Inputs to the
ADC may be selected from the following analog signals: tele-
phony (PHONE_IN), mono microphone (MIC1 or MIC2),
stereo line (LINE_IN), auxiliary line input (AUX), stereo CD
ROM (CD), stereo audio from a video source (VIDEO) and
post-mixed stereo or mono line output (LINE_OUT).
Analog Mixing
PHONE_IN, MIC1 or MIC2, LINE_IN, AUX, CD and
VIDEO can be mixed in the analog domain with the stereo
output from the DACs. Each channel of the stereo analog in-
puts may be independently gained or attenuated from +12 dB
to 34.5 dB in 1.5 dB steps. The summing path for the mono
inputs (PHONE_IN, MIC1, and MIC2 to LINE_OUT) dupli-
cates mono channel data on both the left and right LINE_OUT.
Additionally, the PC attention signal (PC_BEEP) may be
mixed with the line output. A switch allows the output of the
DACs to bypass the Phat Stereo 3D enhancement.
Analog-to-Digital Signal Path
The selector sends left and right channel signals to the program-
mable gain amplifier (PGA). The PGA following the selector
allows independent gain for each channel entering the ADC
from 0 dB to +22.5 dB in 1.5 dB steps.
Each channel of the ADC is independent, and can process
left and right channel data at different sample rates. All pro-
grammed sample rates from 7 kHz to 48 kHz have a resolution
of 1 Hz. The AD1819B also supports irrational V.34 sample
rates.
Sample Rates and D
2
S
The AD1819B default mode sets the codec to operate at 48 kHz
sample rates. The converter pairs may process left and right
channel data at different sample rates. The AD1819B sample
rate generator allows the codec to instantaneously change and
process sample rates from 7 kHz to 48 kHz with a resolution of
1 Hz. The in-band integrated noise and distortion artifacts in-
troduced by rate conversions are below 90 dB. The AD1819B
uses a 4-bit D/A structure and Data Directed Scrambling (D
2
S)
to enhance noise immunity on motherboards and in PC enclo-
sures, and to suppress idle tones below the device's quantization
noise floor. The D
2
S process pushes noise and distortion arti-
facts caused by errors in the multibit D/A conversion process to
frequencies beyond the audible range of the human ear and then
filters them.
Digital-to-Analog Signal Path
The analog output of the DAC may be gained or attenuated
from +12 dB to 34.5 dB in 1.5 dB steps, and summed with any
of the analog input signals. The summed analog signal enters
the Master Volume stage where each channel of the mixer out-
put may be attenuated from 0 dB to 46.5 dB in 1.5 dB steps or
muted.
Host-Based Echo Cancellation Support
The AD1819B supports time correlated I/O data format by
presenting mic data on the left channel of the ADC and the
mono summation of left and right output on the right channel.
The ADC is splittable; left and right ADC data can be sampled
at different rates.
Telephony Modem Support
The AD1819B contains a V.34-capable analog front end for
supporting host-based and data pump modems. The modem
DAC typical dynamic range is 90 dB over a 4.2 kHz analog
output passband where F
S
= 12.8 kHz. The left channel of the
ADC and DAC may be used to convert modem data at the same
sample rate in the range between 7 kHz and 48 kHz. All pro-
grammed sample rates have a resolution of 1 Hz. The AD1819B
supports irrational V.34 sample rates with 8/7 and 10/7 select-
able sample rate multiplier coefficients.
Differences Between the AD1819A and AD1819B
The voltage reference (V
REF
) of the AD1819B remains active
while
RESET is asserted. This eliminates the audible artifacts
associated with the
RESET LO to HI transitions that can
occur during a Windows boot (power-up) or Windows warm
restart (reset).
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AD1819B
STANDARD TEST CONDITIONS UNLESS OTHERWISE NOTED
DAC Test Conditions
Temperature
25
C
Calibrated
Digital Supply (V
DD
)
5.0
V
0 dB Attenuation
Analog Supply (V
CC
)
5.0
V
Input 0 dB
Sample Rate (F
S
)
48
kHz
10 k
Output Load
Input Signal
1008
Hz
Mute Off
Analog Output Passband
20 Hz to 20 kHz
ADC Test Conditions
V
IH
(AC-Link)
2.0
V
Calibrated
V
IL
(AC-Link)
0.8
V
0 dB Gain
V
IH
(CS0, CS1, CHAIN_IN)
4.0
V
Input 3 dB Relative to Full Scale
V
IL
(CHAIN_CLK)
1.0
V
Line Input Selected
ANALOG INPUT
Parameter
Min
Typ
Max
Units
Input Voltage (RMS Values Assume Sine Wave Input)
LINE_IN, AUX, CD, VIDEO, PHONE_IN, PC_BEEP
1
V rms
2.83
V p-p
MIC1, MIC2 with +20 dB Gain (M20 = 1)
0.1
V rms
0.283
V p-p
MIC1, MIC2 with 0 dB Gain (M20 = 0)
1
V rms
2.83
V p-p
Input Impedance*
10
k
Input Capacitance*
15
pF
PROGRAMMABLE GAIN AMPLIFIER--ADC
Parameter
Min
Typ
Max
Units
Step Size (0 dB to 22.5 dB)
1.5
dB
PGA Gain Range Span
22.5
dB
ANALOG MIXER-- INPUT GAIN/AMPLIFIERS/ATTENUATORS
Parameter
Min
Typ
Max
Units
Dynamic Range (60 dB Input THD+N, Referenced to Full Scale, A-Weighted)
CD to LINE_OUT
90
dB
Other to LINE_OUT*
90
dB
Step Size (+12 dB to 34.5 dB): (All Steps Tested)
MIC, LINE_IN, AUX, CD, VIDEO, PHONE_IN, DAC
1.5
dB
Input Gain/Attenuation Range
MIC, LINE_IN, AUX, CD, VIDEO, PHONE_IN, DAC
46.5
dB
Step Size (0 dB to 45 dB): (All Steps Tested)
PC_BEEP
3.0
dB
Input Gain/Attenuation Range: PC_BEEP
45
dB
DIGITAL DECIMATION AND INTERPOLATION FILTERS*
Parameter
Min
Typ
Max
Units
Passband
0
0.4
F
S
Hz
Passband Ripple
0.09
dB
Transition Band
0.4
F
S
0.6
F
S
Hz
Stopband
0.6
F
S
Hz
Stopband Rejection
74
dB
Group Delay
12/F
S
sec
Group Delay Variation Over Passband
0.0
s
*Guaranteed, not tested.
Specifications subject to change without notice.
SPECIFICATIONS
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AD1819BSPECIFICATIONS
ANALOG-TO-DIGITAL CONVERTERS
Parameter
Min
Typ
Max
Units
Resolution
16
Bits
Total Harmonic Distortion (THD)
0.02
%
74
dB
Dynamic Range (60 dB Input THD+N Referenced to Full Scale,
A-Weighted)
84
87
dB
Signal-to-Intermodulation Distortion* (CCIF Method)
85
dB
ADC Crosstalk*
Line Inputs (Input L, Ground R, Read R; Input R, Ground L, Read L)
100
90
dB
Line to Other
90
85
dB
Gain Error (Full-Scale Span Relative to Nominal Input Voltage)
10
%
Interchannel Gain Mismatch (Difference of Gain Errors)
0.5
dB
ADC Offset Error
5
mV
DIGITAL-TO-ANALOG CONVERTERS
Parameter
Min
Typ
Max
Units
Resolution
16
Bits
Total Harmonic Distortion (THD) LINE_OUT
0.02
%
74
dB
Dynamic Range (60 dB Input THD+N Referenced to Full Scale,
A-Weighted)
85
90
dB
Signal-to-Intermodulation Distortion* (CCIF Method)
85
dB
Gain Error (Full-Scale Span Relative to Nominal Input Voltage)
10
%
Interchannel Gain Mismatch (Difference of Gain Errors)
0.5
dB
DAC Crosstalk* (Input L, Zero R, Measure LINE_OUT_R; Input R,
dB
Zero L, Measure LINE_OUT_L)
80
dB
Total Out-of-Band Energy (Measured from 0.6
F
S
to 20 kHz)*
40
dB
MASTER VOLUME
Parameter
Min
Typ
Max
Units
Step Size (0 dB to 46.5 dB)
LINE_OUT_L, LINE_OUT_R, MONO_OUT
1.5
dB
Output Attenuation Range Span
46.5
dB
Mute Attenuation of 0 dB Fundamental*
75
dB
ANALOG OUTPUT
Parameter
Min
Typ
Max
Units
Full-Scale Output Voltage
1
V rms
2.83
V p-p
Output Impedance*
800
External Load Impedance
10
k
Output Capacitance*
15
pF
External Load Capacitance
100
pF
V
REF
2.00
2.25
2.50
V
V
REF
Current Drive
100
A
V
REFOUT
2.25
V
V
REFOUT
Current Drive
5
mA
Mute Click (Muted Output Minus Unmuted Midscale DAC Output)*
5
mV
*Guaranteed, not tested.
Specifications subject to change without notice.
STATIC DIGITAL SPECIFICATIONS
Parameter
Min
Typ
Max
Units
High-Level Input Voltage (V
IH
): Digital Inputs
0.4
DV
DD
V
Low-Level Input Voltage (V
IL
)
0.2
DV
DD
V
High-Level Output Voltage (V
OH
), I
OH
= 2 mA
0.5
DV
DD
V
Low-Level Output Voltage (V
OL
), I
OL
= 2 mA
0.2
DV
DD
V
Input Leakage Current
10
10
A
Output Leakage Current
10
10
A
POWER SUPPLY
Parameter
Min
Typ
Max
Units
Power Supply Range--Analog
4.5
5.5
V
Power Supply Range--Digital
4.5
5.5
V
Power Supply Current
120
mA
Power Dissipation
600
mW
Analog Supply Current
60
mA
Digital Supply Current
60
mA
Power Supply Rejection (100 mV p-p Signal @ 1 kHz)*
(At Both Analog and Digital Supply Pins, Both ADCs and DACs)
40
dB
CLOCK SPECIFICATIONS*
Parameter
Min
Typ
Max
Units
Input Clock Frequency
24.576
MHz
Recommended Clock Duty Cycle
40
50
60
%
POWER-DOWN STATES
Parameter
Set Bits
Min
Typ
Max
Units
ADCs and Input Mux Power-Down
PR0
110
mA
DACs Power-Down
PR1
100
mA
Analog Mixer Power-Down (V
REF
and V
REFOUT
On)
PR1, PR2
54
mA
Analog Mixer Power-Down (V
REF
and V
REFOUT
Off)
PR0, PR1, PR3
47
mA
Digital Interface Power-Down*
PR4
120
mA
Internal Clocks Disabled*
PR0, PR1, PR4, PR5
85
mA
ADC and DAC Power-Down
PR0, PR1
85
mA
V
REF
Standby Mode*
PR0, PR1, PR2, PR4, PR5
55
mA
Total Power-Down
PR0, PR1, PR2, PR3,
PR4, PR5
220
A
RESET (Low)
250
A
*Guaranteed, not tested.
Specifications subject to change without notice.
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AD1819B