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99dB Stereo DAC
DESCRIPTION
WM8725 is a high-performance stereo DAC designed for
use in portable audio equipment, video CD players and
2
similar applications. It comprises selectable normal or I S
compatible serial data interfaces for 16 to 24-bit digital
inputs, high performance digital filters, and sigma-delta
output DACs, achieving an excellent 99dB signal-to-noise
performance.
The device is available in a 14-lead SOIC package that
offers selectable mute and de-emphasis functions using a
minimum of external components.
WM8725
FEATURES
99dB SNR performance
Stereo DAC with input sampling from 8kHz to 96kHz
Additional mute feature
2
Normal or I S compatible data format
Sigma-delta design with 64x oversampling
System clock 256fs or 384fs
Supply range 3V to 5V
14-lead SOIC package
APPLICATIONS
Portable audio equipment
Video CD players
BLOCK DIAGRAM
WOLFSON MICROELECTRONICS plc
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Production Data, February 2012, Rev 4.3
Copyright
2012
Wolfson Microelectronics plc
.
WM8725
TABLE OF CONTENTS
Production Data
DESCRIPTION ................................................................................................................ 1
FEATURES ..................................................................................................................... 1
APPLICATIONS.............................................................................................................. 1
BLOCK DIAGRAM ......................................................................................................... 1
TABLE OF CONTENTS .................................................................................................. 2
PIN CONFIGURATION ................................................................................................... 3
ORDERING INFORMATION ........................................................................................... 3
ABSOLUTE MAXIMUM RATINGS ................................................................................. 4
RECOMMENDED OPERATING CONDITIONS .............................................................. 4
ELECTRICAL CHARACTERISTICS .............................................................................. 5
PIN DESCRIPTION ......................................................................................................... 6
INTERNAL POWER ON RESET ............................................................................................... 6
DEVICE DESCRIPTION ................................................................................................. 8
INTRODUCTION ....................................................................................................................... 8
DAC CIRCUITS ......................................................................................................................... 8
SERIAL DATA INTERFACE ...................................................................................................... 9
SYSTEM CLOCK ..................................................................................................................... 10
RECOMMENDED EXTERNAL COMPONENTS........................................................... 11
DETAIL OF RECOMMENDED EXTERNAL COMPONENTS SHOWING THE EXTERNAL
LOW PASS FILTER................................................................................................................. 11
PCB LAYOUT .......................................................................................................................... 11
PACKAGE DIMENSIONS ............................................................................................. 12
ADDRESS: .............................................................................................................................. 13
REVISION HISTORY .................................................................................................... 14
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PD, Rev 4.3, February 2012
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WM8725
Production Data
PIN CONFIGURATION
LRCIN
DIN
BCKIN
NC
CAP
VOUTR
GND
1
2
3
4
5
6
7
14
13
SCKI
FORMAT
DEEMPH
NC
MUTE
VOUTL
VDD
WM8725
12
11
10
9
8
ORDERING INFORMATION
DEVICE
WM8725CGED
WM8725CGED/R
TEMPERATURE
RANGE
-40 C to +85 C
-40 C to +85 C
o
o
o
o
PACKAGE
14-lead SOIC
(lead free)
14-lead SOIC
(Pb-free, tape and reel)
MOISTURE SENSITIVITY
LEVEL
MSL1
MSL1
PEAK BODY
TEMPERATURE
260 C
260 C
o
o
Note:
Reel quantity: 3,000
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WM8725
ABSOLUTE MAXIMUM RATINGS
Production Data
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.
Wolfson tests its package types according to IPC/JEDEC J-STD-020B for Moisture Sensitivity to determine acceptable storage
conditions prior to surface mount assembly. These levels are:
MSL1 = unlimited floor life at <30C / 85% Relative Humidity. Not normally stored in moisture barrier bag.
MSL2 = out of bag storage for 1 year at <30C / 60% Relative Humidity. Supplied in moisture barrier bag.
MSL3 = out of bag storage for 168 hours at <30C / 60% Relative Humidity. Supplied in moisture barrier bag.
The Moisture Sensitivity Level for each package type is specified in Ordering Information.
CONDITION
Supply voltage
Reference input
Operating temperature range, T
A
Storage temperature
Lead temperature (soldering, 10 seconds)
Lead temperature (soldering, 2 minutes)
-40 C
-65 C
o
o
MIN
-0.3V
MAX
+7.0V
VCC+0.3V
+85 C
+150 C
+240 C
+183 C
o
o
o
o
RECOMMENDED OPERATING CONDITIONS
PARAMETER
Supply Range
Ground
Supply Current
SYMBOL
VDD
GND
VDD = 5V
VDD = 3V
TEST
CONDITIONS
MIN
-10%
TYP
3.0 to 5.0
0
15
7.5
25
MAX
+10%
UNIT
V
V
mA
mA
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WM8725
ELECTRICAL CHARACTERISTICS
Test Conditions
V
DD
= 5V, GND = 0V, T
A
= +25 C, fs = 48kHz, SCKI = 256fs unless otherwise stated.
PARAMETER
Digital Logic Levels
Input LOW level
Input HIGH level
Analogue Output Levels
Load Resistance
To midrail or AC coupled
(5V supply)
To midrail or AC coupled
(3V supply)
Maximum capacitance load
Output DC level
Reference Levels
Potential divider resistance
Voltage at CAP
DAC Circuit Specifications
SNR (Note 1)
Full scale output voltage
THD (Full scale)
THD+N (Dynamic range)
Frequency response
Transition band
Out of band rejection
Channel Separation
Gain mismatch
channel-to-channel
Audio Data Input and System Clock Timing Information
BCKIN pulse cycle time
BCKIN pulse width high
BCKIN pulse width low
BCKIN rising edge to LRCIN edge
LRCIN rising edge to BCKIN
rising edge
DIN setup time
DIN hold time
System clock pulse width high
System clock pulse width low
Notes:
1.
2.
t
BCY
t
BCH
t
BCL
t
BL
t
LB
t
DS
t
DH
t
SCKIH
t
SCKIL
100
50
50
30
30
30
30
13
13
VDD = 5V
VDD = 3V
Into 10kohm VDD = 5V, 0dB
Into 10kohm VDD = 3V, 0dB
0dB
-60dB
0
20,000
-40
90
±1
±5
0.9
90
99
97
1.0
0.6
0.01
92
0.02
1.1
V
DD
to CAP and CAP to GND
VDD = 5V
80
2.3
100
2.5
120
2.7
5V or 3V
1
1
100
V
DD
/2
V
IL
V
IH
2.0
0.8
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
o
Production Data
UNIT
V
V
kΩ
kΩ
pF
V
kΩ
V
dB
dB
V
RMS
V
RMS
%
dB
Hz
Hz
dB
dB
%FSR
20,000
ns
ns
ns
ns
ns
ns
ns
ns
ns
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.
All performance measurements done with 20kHz low pass 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.
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