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Электронный компонент: WM8711

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WM8711
Internet Audio DAC with Integrated Headphone Driver
Product Preview, Novembert 2000, 1.2
WOLFSON MICROELECTRONICS LTD
Lutton Court, Bernard Terrace, Edinburgh, EH8 9NX, UK
Tel: +44 (0) 131 667 9386
Fax: +44 (0) 131 667 5176
Email: sales@wolfson.co.uk
http://www.wolfson.co.uk
Product Preview data sheets contain
specifications for products in the formative
phase of development. These products may
be changed or discontinued without notice.
2000 Wolfson Microelectronics Ltd
.
DESCRIPTION
The WM8711 is a low power stereo DAC with an integrated
headphone driver. The WM8711 is designed specifically for
portable MP3 audio and speech players. The WM8711 is
also ideal for MD, CD machines and DAT players.
Stereo 24-bit multi-bit sigma delta DACs are used with
oversampling digital interpolation filters. Digital audio input
word lengths from 16-32 bits and sampling rates from 8KHz
to 96KHz are supported.
Stereo audio outputs are buffered for driving headphones
from a programmable volume control, line level outputs are
also provided along with anti-thump mute and power
up/down circuitry.
The device is controlled via a 2 or 3 wire serial interface.
The interface provides access to all features including
volume controls, mutes, de-emphasis and extensive power
management facilities. The device is available in a small 28-
pin SSOP package.
A USB mode is provided where all audio rates can be
derived from a single 12MHz MCLK, saving on the need for
a PLL or multiple crystals.
FEATURES
Audio
Performance
-
100dB SNR (`A' weighted @ 48kHz) DAC
-
1.42 3.6V Digital Supply Operation
-
2.7 3.6V Analogue Supply Operation
DAC Sampling Frequency: 8KHz 96KHz
2 or 3-Wire MPU Serial Control Interface
Programmable Audio Data Interface Modes
-
I
2
S, Left, Right Justified or DSP
-
16/20/24/32 bit Word Lengths
-
Master or Slave Clocking Mode
Stereo Audio Outputs
Output Volume and Mute Controls
Highly Efficient Headphone Driver
Playback Mode Power Consumption < 18mW
28-Pin SSOP Package
APPLICATIONS
Portable MP3 Players
CD and Minidisc Players
BLOCK DIAGRAM
XT
I
/
M
C
L
K
XT
O
CL
KO
UT
DIGITAL
FILTERS
CONTROL INTERFACE
VOL/
MUTE
VOL/
MUTE
H/P
DRIVER
H/P
DRIVER
CSB
SDI
N
SCL
K
(10) RHPOUT
(9) LHPOUT
(13) ROUT
(12) LOUT
DB
V
D
D
(3.
3
V
)
DGN
D
+6 to -73dB
1 dB Steps
(8) HPVDD
(11) HPGND
+6 to -73dB
1 dB Steps
DC
V
D
D
(1.
5
V
)
MO
D
E
DIG
T
AL AUDIO

I
N
TE
RF
ACE
DACLRC (5)
BCLK (3)
DACDAT (4)
AVD
D
AGN
D
VM
I
D
MUTE
MUTE
DAC
DAC
(20) LLINEIN
(19) RLINEIN
OSC
CLKIN
DIVIDER
(Div x1, x2)
CLKIN
DIVIDER
(Div x1, x2)
WM8711
(22)
(23)
(24)
(21)
(14)
(16)
(15)
(26)
(25)
(2)
(27)
(1)
(28)
WM8711
Product Preview
WOLFSON MICROELECTRONICS LTD
PP Rev 1.2 November 2000
2
PIN CONFIGURATION
ORDERING INFORMATION
DEVICE
TEMP. RANGE
PACKAGE
XWM8711EDS
-10 to +70
o
C
28-pin SSOP
1
AVDD
2
AGND
3
NC
4
VMID
5
NC
6
RLINEIN
7
LLINEIN
8
DCVDD
9
MODE
10
CSB
SDIN
SCLK
XTO
XTI/MCLK
15
CLKOUT
DGND
NC
NC
DACDAT
DACLRC
BCLK
DBVDD
LHPOUT
HPGND
HPVDD
RHPOUT
LOUT
ROUT
11
12
13
14
16
17
18
19
20
21
22
23
24
25
28
27
26
PIN DESCRIPTION
PIN
NAME
TYPE
DESCRIPTION
1
DBVDD
Supply
Digital Buffers VDD
2
CLKOUT
Digital Output
Buffered Clock Output
3
BCLK
Digital Input/Output
Digital Audio Bit Clock, Pull Down (see Note 1)
4
DACDAT
Digital Input
DAC Digital Audio Data Input
5
DACLRC
Digital Input/Output
DAC Sample Rate Left/Right Clock, Pull Down (see Note 1)
6
NC
No Connection
7
NC
No Connection
8
HPVDD
Supply
Headphone VDD
9
LHPOUT
Analogue Output
Left Channel Headphone Output
10
RHPOUT
Analogue Output
Right Channel Headphone Output
11
HPGND
Ground
Headphone GND
12
LOUT
Analogue Output
Left Channel Line Output
13
ROUT
Analogue Output
Right Channel Line Output
14
AVDD
Supply
Analogue VDD
15
AGND
Ground
Analogue GND
16
VMID
Analogue Output
Mid-rail reference decoupling point
17
NC
No Connection
18
NC
No Connection
19
RLINEIN
Analogue Input
Right Channel Line Input (AC coupled)
20
LLINEIN
Analogue Input
Left Channel Line Input (AC coupled)
21
MODE
Digital Input
Control Interface Selection, Pull up (see Note 1)
22
CSB
Digital Input
3-Wire MPU Chip Select/ 2-Wire MPU interface address selection, active
low, Pull up (see Note 1)
23
SDIN
Digital Input
3-Wire MPU Data Input / 2-Wire MPU Data Input
24
SCLK
Digital Input
3-Wire MPU Clock Input / 2-Wire MPU Clock Input
25
XTI/MCLK
Digital Input
Crystal Input or Master Clock Input (MCLK)
26
XTO
Digital Output
Crystal Output
27
DCVDD
Supply
Digital Core VDD
28
DGND
Ground
Digital GND
Note:
1.
Pull Up/Down only present when Control Register Interface ACTIVE=0 to conserve power.
WM8711
Product Preview
WOLFSON MICROELECTRONICS LTD
PP Rev 1.2 November 2000
3
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings are stress ratings only. Permanent damage to the device may be caused by continuously operating at
or beyond these limits. Device functional operating limits and guaranteed performance specifications are given under Electrical
Characteristics at the test conditions specified.
ESD Sensitive Device. This device is manufactured on a CMOS process. It is therefore generically susceptible
to damage from excessive static voltages. Proper ESD precautions must be taken during handling and storage
of this device.
CONDITION
MIN
MAX
Digital supply voltage
-0.3V
+3.63V
Analogue supply voltage
-0.3V
+3.63V
Voltage range digital inputs
DGND -0.3V
DVDD +0.3V
Voltage range analogue inputs
AGND -0.3V
AVDD +0.3V
Master Clock Frequency (see Note 4)
40MHz
Operating temperature range, T
A
-10
C
+70
C
Storage temperature
-65
C
+150
C
Package body temperature (soldering 10 seconds)
+240
C
Package body temperature (soldering 2 minutes)
+183
C
Notes:
1.
Analogue and digital grounds must always be within 0.3V of each other.
2.
The digital supply core voltage (DCVDD) must always be less than or equal to the analogue supply voltage (AVDD) or
digital supply buffer voltage (DBVDD).
3.
The digital supply buffer voltage (DBVDD) must always be less than or equal to the analogue supply voltage (AVDD).
4.
When CLKIDIV2 = 1.
WM8711
Product Preview
WOLFSON MICROELECTRONICS LTD
PP Rev 1.2 November 2000
4
RECOMMENDED OPERATING CONDITIONS
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Digital supply range (Core)
DCVDD
1.42
3.6
V
Digital supply range (Buffer)
DBVDD
2.7
3.6
V
Analogue supply range
AVDD, HPVDD
2.7
3.6
V
Ground
DGND,AGND,HPGND
0
V
Total analogue supply current
IAVDD, IHPVDD
DCVDD, DBVDD, AVDD,
HPVDD= 3.3V
8
mA
Digital supply current
IDCVDD, IDBVDD
DCVDD, DBVDD, AVDD,
HPVDD= 3.3V
3
mA
Standby Current Consumption
10
uA
ELECTRICAL CHARACTERISTICS
Test Conditions
AVDD, HPVDD, DBVDD = 3.3V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, T
A
= +25
o
C, Slave Mode, fs = 48kHz, MCLK =
256fs unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Digital Logic Levels (CMOS Levels)
Input LOW level
V
IL
.3 x DBVDD
V
Input HIGH level
V
IH
.7 x DBVDD
V
Output LOW
V
OL
0.10 x
DBVDD
V
Output HIGH
V
OH
.9 x DBVDD
V
Power On Reset Threshold (DCVDD)
DCVDD Threshold On -> Off
V
th
0.7
0.9
1.2
V
Hysteresis
V
IH
0.3
V
DCVDD Threshold Off -> On
V
OL
0.6
V
Analogue Reference Levels
Reference voltage
V
VMID
AVDD/2
50mV
AVDD/2
AVDD/2 +
50mV
V
Potential divider resistance
R
VMID
40K
50K
60K
Ohms
Line Output for DAC Playback Only (Load
= 10K ohms. 50pF)
0dBFs Full scale output voltage
At LINE outputs
1.0 x
AVDD/3.3
Vrms
SNR (Note 1,2)
A-weighted,
@ fs = 48KHz
90
100
dB
SNR (Note 1,2)
A-weighted
@ fs = 96KHz
98
dB
SNR (Note 1,2)
A-weighted,
@ fs = 48KHz, AVDD
= 2.7V
93
dB
Dynamic Range (Note 2)
DNR
A-weighted, -60dB
full scale input
85
90
dB
1KHz, 0dBFs
-88
-80
dB
THD
1kHz, -3dBFs
-92
-86
dB
Power Supply Rejection Ratio
PSSR
1kHz 100mVpp
50
dB
20Hz to 20kHz
100mVpp
45
dB
DAC channel separation
100
dB
WM8711
Product Preview
WOLFSON MICROELECTRONICS LTD
PP Rev 1.2 November 2000
5
Test Conditions
AVDD, HPVDD, DBVDD = 3.3V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, T
A
= +25
o
C, Slave Mode, fs = 48kHz, MCLK =
256fs unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Stereo Headphone Output
0dB Full scale output voltage
1.0 x
AVDD/3.3
Vrms
Max Output Power RL = 32
ohms
P
O
30
mW
Max Output Power RL = 16
ohms
P
O
40
mW
SNR (Note 1,2)
A-weighted
90
97
dB
1kHz, R
L
= 32 ohms @
P
O
= 10mW rms
0.1
60
0.1
60
%
dB
THD
1kHz, R
L
= 32 ohms @
P
O
= 20mW rms
1.0
40
1.0
40
%
dB
Power Supply Rejection Ratio
PSSR
1kHz 100mVpp
50
dB
20Hz to 20kHz
100mVpp
45
dB
Programmable Gain Maximum
Programmable Gain Minimum
1kHz
6
-73
dB
Programmable Gain Step Size
1kHz
1
dB
Mute attenuation
1kHz, 0dB
80
dB
Notes:
1.
Ratio of output level with 1kHz full scale input, to the output level with all zeros into the digital input, measured `A'
weighted over a 20Hz to 20kHz bandwidth.
2.
All performance measurements done with 20kHz low pass filter, and where noted an A-weight filter. Failure to use
such a filter will result in higher THD+N and lower SNR and Dynamic Range readings than are found in the Electrical
Characteristics. The low pass filter removes out of band noise; although it is not audible it may affect dynamic
specification values.
3.
VMID decoupled with 10uF and 0.1uF capacitors (smaller values may result in reduced performance).
TERMINOLOGY
1.
Signal-to-noise ratio (dB) - SNR is a measure of the difference in level between the full scale output and the output
with no signal applied. (No Auto-zero or Automute function is employed in achieving these results).
2.
Dynamic range (dB) - DNR is a measure of the difference between the highest and lowest portions of a signal.
Normally a THD+N measurement at 60dB below full scale. The measured signal is then corrected by adding the 60dB
to it. (e.g. THD+N @ -60dB= -32dB, DR= 92dB).
3.
THD+N (dB) - THD+N is a ratio, of the rms values, of (Noise + Distortion)/Signal.
4.
Stop band attenuation (dB) - Is the degree to which the frequency spectrum is attenuated (outside audio band).
5.
Channel Separation (dB) - Also known as Cross-Talk. This is a measure of the amount one channel is isolated from
the other. Normally measured by sending a full scale signal down one channel and measuring the other.
6.
Pass-Band Ripple - Any variation of the frequency response in the pass-band region.