WOLFSON WM8523

WM8523
w
24-bit 192kHz Stereo DAC with 2Vrms Ground Referenced Line Output
DESCRIPTION
The WM8523 is a stereo DAC with integral charge pump
and software control interface. This provides 2Vrms line
driver outputs using a single 3.3V power supply rail.
The device features ground-referenced outputs and the use
of a DC servo to eliminate the need for line driving coupling
capacitors and effectively eliminate power on pops and
clicks.
The device is controlled and configured either via the
I2C/SPI compliant serial control interface or a hardware
control interface.
The device supports all common audio sampling rates
between 8kHz and 192kHz using all common MCLK fs
rates. Master and Slave modes are available and deemphasis is also supported.
The WM8523 has a 3.3V tolerant digital interface, allowing
logic up to 3.3V to be connected.
FEATURES
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High performance stereo DAC with ground referenced line
driver
Audio Performance
−
106dB SNR (‘A-weighted’)
−
-89dB THD @ -1dBFS
Digital Volume control ranging from -100dB to +12dB
120dB mute attenuation
All common sample rates from 8kHz to 192kHz supported
I2C/SPI compatible and hardware control modes
Data formats: LJ, RJ, I2S, DSP
De-emphasis supported
Maximum 1mV DC offset on Line Outputs
Pop/Click suppressed Power Up/Down Sequencer
AVDD and LINEVDD +3.3V ±10% allowing single supply
20-lead TSSOP or 24-lead QFN packages
Operating temperature range: -40°C to 85°C
APPLICATIONS
•
The device is available in a 20-lead TSSOP or 24-lead
QFN.
WOLFSON MICROELECTRONICS plc
To receive regular email updates, sign up at http://www.wolfsonmicro.com/enews
Consumer digital audio applications requiring 2Vrms output
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Set Top Box
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Digital TV
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DVD Players
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Games Consoles
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A/V Receivers
Production Data, August 2011, Rev 4.1
Copyright ©2011 Wolfson Microelectronics plc
WM8523
Production Data
ZFLAG
CIFMODE
CS/MUTE
SCLK/AIFMODE1
SDA/AIFMODE0
SDOUT/DEEMPH
BLOCK DIAGRAM
W
CONTROL INTERFACE
MCLK
BCLK
LRCLK
DACDAT
DIGITAL
AUDIO
INTERFACE
WM8523
LEFT
DAC
LINEVOUTL
RIGHT
DAC
LINEVOUTR
DIGITAL
FILTERS
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LINEGND
LINEVDD
CPVOUTN
CPCB
CPCA
AVDD
VMID
AGND
CHARGE PUMP
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TABLE OF CONTENTS
DESCRIPTION ................................................................................................................... 1
FEATURES......................................................................................................................... 1
APPLICATIONS ................................................................................................................. 1
BLOCK DIAGRAM ............................................................................................................. 2
TABLE OF CONTENTS ..................................................................................................... 3
PIN CONFIGURATION ....................................................................................................... 4
ORDERING INFORMATION .............................................................................................. 4
PIN DESCRIPTION – 20-LEAD TSSOP ............................................................................ 5
PIN DESCRIPTION – 24-LEAD QFN ................................................................................. 6
ABSOLUTE MAXIMUM RATINGS ..................................................................................... 8
RECOMMENDED OPERATING CONDITIONS ................................................................. 8
ELECTRICAL CHARACTERISTICS .................................................................................. 9
TERMINOLOGY .......................................................................................................................... 9
POWER CONSUMPTION MEASUREMENTS .......................................................................... 10
SIGNAL TIMING REQUIREMENTS ................................................................................. 11
SYSTEM CLOCK TIMING ......................................................................................................... 11
AUDIO INTERFACE TIMING – MASTER MODE ...................................................................... 11
AUDIO INTERFACE TIMING – SLAVE MODE .......................................................................... 12
2
CONTROL INTERFACE TIMING – I C MODE .......................................................................... 13
CONTROL INTERFACE TIMING – SPI MODE ......................................................................... 14
POWER ON RESET CIRCUIT .................................................................................................. 15
DEVICE DESCRIPTION ................................................................................................... 17
INTRODUCTION ....................................................................................................................... 17
SOFTWARE CONTROL INTERFACE....................................................................................... 17
DIGITAL AUDIO INTERFACE ................................................................................................... 21
DIGITAL AUDIO INTERFACE CONTROL ................................................................................. 24
DIGITAL AUDIO DATA SAMPLING RATES .............................................................................. 26
DAC FEATURES ....................................................................................................................... 27
HARDWARE CONTROL INTERFACE ...................................................................................... 32
POWER DOMAINS ................................................................................................................... 34
REGISTER MAP............................................................................................................... 35
REGISTER BITS BY ADDRESS ............................................................................................... 36
DIGITAL FILTER CHARACTERISTICS ........................................................................... 40
DAC FILTER RESPONSES....................................................................................................... 41
DIGITAL DE-EMPHASIS CHARACTERISTICS ......................................................................... 42
APPLICATIONS INFORMATION ..................................................................................... 43
RECOMMENDED EXTERNAL COMPONENTS – 20-LEAD TSSOP......................................... 43
RECOMMENDED PCB LAYOUT – 20-LEAD TSSOP ............................................................... 44
RECOMMENDED EXTERNAL COMPONENTS – 24-LEAD QFN ............................................. 45
RECOMMENDED PCB LAYOUT – 24-LEAD QFN .................................................................... 46
RECOMMENDED ANALOGUE LOW PASS FILTER ................................................................ 47
RELEVANT APPLICATION NOTES .......................................................................................... 47
PACKAGE DIMENSIONS – 20-LEAD TSSOP ................................................................ 48
PACKAGE DIMENSIONS – 24-LEAD QFN ..................................................................... 49
IMPORTANT NOTICE ...................................................................................................... 50
ADDRESS ................................................................................................................................. 50
REVISION HISTORY ........................................................................................................ 51
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PIN CONFIGURATION
24
23
22
21
20
19
DACDAT
1
18
NC
LRCLK
2
17
LINEVOUTL
BCLK
3
16
LINEVOUTR
MCLK
4
15
NC
SDOUT/DEEMPH
5
14
AVDD
SDA/AIFMODE0
6
13
AVDD
7
20-LEAD TSSOP
8
9
10
11
12
24-LEAD QFN (TOP VIEW)
ORDERING INFORMATION
ORDER CODE
TEMPERATURE
RANGE
PACKAGE
MOISTURE
SENSITIVITY LEVEL
PEAK SOLDERING
TEMPERATURE
WM8523GEDT
−40°C to +85°C
20-lead TSSOP
(pb-free)
MSL1
260oC
WM8523GEDT/R
−40°C to +85°C
20-lead TSSOP
(pb-free, tape and reel)
MSL1
260oC
WM8523GEFL/V
−40°C to +85°C
24-lead QFN
(pb-free)
MSL3
260oC
WM8523GEFL/RV
−40°C to +85°C
24-lead QFN
(pb-free, tape and reel)
MSL3
260oC
Note:
TSSOP Reel quantity = 2000
QFN Reel quantity = 3500
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PIN DESCRIPTION – 20-LEAD TSSOP
PIN NO
NAME
TYPE
DESCRIPTION
1
LINEVOUTL
Analogue Out
Left line output
2
CPVOUTN
Analogue Out
Charge Pump negative rail decoupling pin
3
CPCB
Analogue Out
Charge Pump fly back capacitor pin
4
LINEGND
Supply
5
CPCA
Analogue Out
6
LINEVDD
Supply
7
ZFLAG
Digital Out
8
DACDAT
Digital In
Digital audio interface data input
9
LRCLK
Digital I/O
Digital audio interface left/right clock
10
BCLK
Digital I/O
Digital audio interface bit clock
11
MCLK
Digital In
Master clock
Charge Pump ground
Charge Pump fly back capacitor pin
Charge Pump supply
Zero flag output
I2C SOFTWARE
MODE
SPI SOFTWARE
MODE
Digital I/O
I2C address select
bit[1]
Serial control interface
data output pin
0 – No de-emphasis
1 – De-emphasis
AIFMODE0
Digital I/O
Internal pull-down
Serial control interface
data input pin
Serial control interface
data input pin
00 – LJ 24 bits
14
SCLK/
AIFMODE1
Digital I/O
Internal pull-down
Serial control interface
clock input pin
Serial control interface
clock input pin
01 – I2S 24 bits
10 – RJ 16 bits
11 – RJ 24 bits
15
CS
¯¯ /
MUTE
¯¯¯¯¯
Digital In
I2C address select
bit[0]
Serial control interface
chip select
0 – Mute enabled
1 – Mute disabled
16
CIFMODE
Digital In
Tri-level
0 – I2C compatible
mode select
1 – SPI compatible
mode select
Z – Hardware mode
17
AGND
Supply
18
VMID
Analogue Out
19
AVDD
Supply
Analogue supply
20
LINEVOUTR
Analogue Out
Right line output
12
13
SDOUT/
DEEMPH
SDA/
HARDWARE MODE
AIFMODE[1:0]
Analogue ground
Analogue midrail decoupling pin
Note: Tri-level pins which require the ‘Z’ state to be selected should be left floating (open)
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PIN DESCRIPTION – 24-LEAD QFN
PIN NO
NAME
TYPE
DESCRIPTION
1
DACDAT
Digital In
Digital audio interface data input
2
LRCLK
Digital I/O
Digital audio interface left/right clock
3
BCLK
Digital I/O
Digital audio interface bit clock
4
MCLK
Digital In
Master clock
I2C SOFTWARE
MODE
SPI SOFTWARE
MODE
HARDWARE MODE
5
SDOUT/
DEEMPH
Digital I/O
I2C address select
bit[1]
Serial control interface
data output pin
6
SDA/
AIFMODE0
Digital I/O
Serial control interface
data input pin
Serial control interface
data input pin
7
SCLK/
AIFMODE1
Digital I/O
Serial control interface
clock input pin
Serial control interface
clock input pin
Digital In
I2C address select
bit[0]
Serial control interface
chip select
0 – Mute enabled
1 – Mute disabled
0 – I2C compatible
1 – SPI compatible
mode select
Z – Hardware mode
8
CS
¯¯ /
MUTE
¯¯¯¯¯
9
CIFMODE
Digital In
Tri-level
10
AGND
Supply
Analogue ground
11
AGND
Supply
Analogue ground
12
VMID
Analogue Out
13
AVDD
Supply
Analogue supply
14
AVDD
Supply
Analogue supply
15
NC
No Connect
16
LINEVOUTR
Analogue Out
Right line output
17
LINEVOUTL
Analogue Out
Left line output
18
NC
No Connect
19
CPVOUTN
Analogue Out
Charge Pump negative rail decoupling pin
20
CPCB
Analogue Out
Charge Pump fly back capacitor pin
21
LINEGND
Supply
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mode select
0 – No de-emphasis
1 – De-emphasis
AIFMODE[1:0]
00 – LJ 24 bits
01 – I2S 24 bits
10 – RJ 16 bits
11 – RJ 24 bits
Analogue midrail decoupling pin
No internal connection
No internal connection
Charge Pump ground
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PIN NO
NAME
TYPE
22
CPCA
Analogue Out
23
LINEVDD
Supply
24
ZFLAG
Digital Out
DESCRIPTION
Charge Pump fly back capacitor pin
Charge Pump supply
Zero flag output
Note: Tri-level pins which require the ‘Z’ state to be selected should be left floating (open)
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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.
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 <30°C / 85% Relative Humidity. Not normally stored in moisture barrier bag.
MSL2 = out of bag storage for 1 year at <30°C / 60% Relative Humidity. Supplied in moisture barrier bag.
MSL3 = out of bag storage for 168 hours at <30°C / 60% Relative Humidity. Supplied in moisture barrier bag.
The Moisture Sensitivity Level for each package type is specified in Ordering Information.
CONDITION
AVDD, LINEVDD
Voltage range digital inputs
Voltage range analogue inputs
MIN
MAX
-0.3V
+4.5V
LINEGND -0.3V
LINEVDD +0.3V
AGND -0.3V
AVDD +0.3V
Temperature range, TA
-40°C
+125°C
Storage temperature after soldering
-65°C
+150°C
Notes
1.
Analogue grounds must always be within 0.3V of each other.
2.
LINEVDD and AVDD must always be within 0.3V of each other.
RECOMMENDED OPERATING CONDITIONS
PARAMETER
SYMBOL
Analogue supply range
AVDD, LINEVDD
Ground
AGND, LINEGND
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TEST CONDITIONS
MIN
TYP
MAX
UNIT
2.97
3.3
3.63
V
0
V
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ELECTRICAL CHARACTERISTICS
Test Conditions
LINEVDD=AVDD=3.3V, LINEGND=AGND=0V, TA=+25°C, Slave Mode, fs=48kHz, MCLK=256fs, 24-bit data, unless otherwise
stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
0dBFS
1.89
2.1
2.31
Vrms
Analogue Output Levels
Output Level
Load Impedance
1
Load Capacitance
kΩ
No external RC filter
300
pF
With filter shown in
Error! Reference
source not found.
1
μF
DAC Performance
Signal to Noise Ratio
SNR
RL = 10kΩ
A-weighted
100
106
dB
RL = 10kΩ
Un-weighted
104
dB
Dynamic Range
DNR
RL = 10kΩ
A-weighted
104
dB
Total Harmonic Distortion
THD
RL = 10kΩ
-1dBFS
-89
dB
RL = 10kΩ
0dBFS
-86
dB
100Hz
54
dB
dB
AVDD + LINEVDD
Power Supply Rejection Ratio
PSRR
Channel Separation
1kHz
54
20kHz
50
dB
1kHz
100
dB
20Hz to 20kHz
95
0
degrees
0.1
dB
System Absolute Phase
Channel Level Matching
Mute Attenuation
dB
-120
DC Offset at LINEVOUTL and
LINEVOUTR
-1
0
dB
1
mV
Digital Logic Levels
Input HIGH Level
VIH
Input LOW Level
VIL
Output HIGH Level
VOH
Output LOW Level
VOL
0.7×
LINEVDD
0.3×
LINEVDD
IOL = 1mA
0.9×
LINEVDD
0.1×
LINEVDD
V
0.9
μA
10
-0.9
V
V
IOH = -1mA
Input Capacitance
Input Leakage
V
pF
TERMINOLOGY
1.
Signal-to-Noise Ratio (dB) – SNR is a measure of the difference in level between the maximum theoretical full scale output signal
and the output with no input signal applied.
2.
Total Harmonic Distortion (dB) – THD is the level of the rms value of the sum of harmonic distortion products relative to the
amplitude of the measured output signal.
3.
All performance measurements carried out with 20kHz low pass filter, and where noted an A-weighted filter. Failure to use such a
filter will result in higher THD and lower SNR 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.
4.
Mute Attenuation – This is a measure of the difference in level between the full scale output signal and the output with mute
applied.
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POWER CONSUMPTION MEASUREMENTS
Test Conditions
LINEVDD=AVDD=3.3V, LINEGND=AGND=0V, TA=+25°C, Slave Mode, quiescent (no signal)
TEST CONDITIONS
IAVDD
ILINEVDD
TOTAL
(mA)
(mA)
(mA)
No clocks applied
SYS_ENA[1:0]=00
0.8
1.1
1.9
Standby
SYS_ENA[1:0]=01
0.2
2.2
2.4
Playback
SYS_ENA[1:0]=11
4.8
6.0
10.8
Standby
SYS_ENA[1:0]=01
0.2
2.9
3.1
Playback
SYS_ENA[1:0]=11
5.5
8.5
14.0
Standby
SYS_ENA[1:0]=01
0.2
2.9
3.1
Playback
SYS_ENA[1:0]=11
5.5
8.5
14.0
Off
fs=48kHz, MCLK=256fs
fs=96kHz, MCLK=256fs
fs=192kHz, MCLK=128fs
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SIGNAL TIMING REQUIREMENTS
SYSTEM CLOCK TIMING
Figure 1 System Clock Timing Requirements
Test Conditions
LINEVDD=AVDD=2.97~3.63V, LINEGND=AGND=0V, TA=+25°C
PARAMETER
SYMBOL
MIN
MCLK cycle time
tMCLKY
27
MCLK high time
tMCLKH
11
MCLK low time
tMCLKL
TYP
MAX
UNIT
500
ns
Master Clock Timing Information
ns
11
MCLK duty cycle (tMCLKH/tMCLKL)
ns
40:60
60:40
%
AUDIO INTERFACE TIMING – MASTER MODE
Figure 2 Master Mode Digital Audio Data Timing
Test Conditions
LINEVDD=AVDD=2.97~3.63, LINEGND=AGND=0V, TA=+25°C, Master Mode
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
16
ns
Audio Data Input Timing Information
LRCLK propagation delay from BCLK falling edge
tDL
4
DACDAT setup time to BCLK rising edge
tDST
22
ns
DACDAT hold time to BCLK falling edge
tDHT
25
ns
Table 1 Master Mode Audio Interface Timing
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AUDIO INTERFACE TIMING – SLAVE MODE
Figure 3 Digital Audio Data Timing – Slave Mode
Test Conditions
LINEVDD=AVDD=2.97~3.63V, LINEGND=AGND=0V, TA=+25°C, Slave Mode
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
Audio Data Input Timing Information
BCLK cycle time
tBCY
27
ns
BCLK pulse width high
tBCH
11
ns
BCLK pulse width low
tBCL
11
ns
LRCLK set-up time to BCLK rising edge
tLRSU
7
ns
LRCLK hold time from BCLK rising edge
tLRH
5
ns
DACDAT hold time from LRCLK rising edge
tDH
5
ns
DACDAT set-up time to BCLK rising edge
tDS
7
ns
Table 2 Slave Mode Audio Interface Timing
Note:
BCLK period should always be greater than or equal to MCLK period.
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2
CONTROL INTERFACE TIMING – I C MODE
I2C mode is selected by driving the CIFMODE pin low.
Figure 4 Control Interface Timing – I2C Control Mode
Test Conditions
LINEVDD=AVDD=2.97~3.63V, LINEGND=AGND=0V, TA=+25°C
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
SCLK Low Pulse-Width
t1
100
400
kHz
ns
SCLK High Pulse-Width
t2
100
ns
Hold Time (Start Condition)
t3
600
ns
Setup Time (Start Condition)
t4
600
ns
Data Setup Time
t5
100
SDA, SCLK Rise Time
t6
SDA, SCLK Fall Time
t7
Setup Time (Stop Condition)
t8
Data Hold Time
t9
Program Register Input Information
SCLK Frequency
Pulse width of spikes that will be suppressed
ns
300
ns
300
ns
900
ns
8
ns
600
2
ns
2
Table 3 Control Interface Timing – I C Control Mode
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CONTROL INTERFACE TIMING – SPI MODE
SPI mode is selected by connecting the CIFMODE pin high.
Figure 5 Control Interface Timing – SPI Control Mode (Read Cycle)
Test Conditions
LINEVDD=AVDD=2.97~3.63V, LINEGND=AGND=0V, TA=+25°C
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
SCLK rising edge to CSB falling edge
tCSU
40
SCLK falling edge to CSB rising edge
tCHO
40
ns
SCLK pulse cycle time
tSCY
160
ns
Program Register Input Information
ns
SCLK pulse width low
tSCL
64
ns
SCLK pulse width high
tSCH
64
ns
SDA to SCLK set-up time
tDSU
20
ns
SDA to SCLK hold time
tDHO
40
SDOUT propagation delay from SCLK falling
edge
tDL
Pulse width of spikes that will be suppressed
tps
2
ns
5
ns
8
ns
Table 4 Control Interface Timing –SPI Control Mode
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POWER ON RESET CIRCUIT
Figure 6 Internal Power on Reset Circuit Schematic
The WM8523 includes an internal Power-On-Reset circuit, as shown in Figure 6, which is used to reset
the DAC digital logic into a default state after power up. The POR circuit is powered by AVDD and has
as its inputs VMID and LINEVDD. It asserts POR low if VMID or LINEVDD are below a minimum
threshold.
Figure 7 Typical Power Timing Requirements
Figure 7 shows a typical power-up sequence where LINEVDD comes up with AVDD. When AVDD goes
above the minimum threshold, Vpora, there is enough voltage for the circuit to guarantee POR is asserted
low and the chip is held in reset. In this condition, all writes to the control interface are ignored. After
VMID rises to Vpord_hi and AVDD rises to Vpora_hi, POR is released high and all registers are in their default
state and writes to the control interface may take place.
On power down, PORB is asserted low whenever LINEVDD or AVDD drop below the minimum threshold
Vpora_low.
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Test Conditions
LINEVDD = AVDD = 3.3V AGND = LINEGND = 0V, TA = +25oC
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Power Supply Input Timing Information
VDD level to POR defined
(LINEVDD/AVDD rising)
Vpora
Measured from LINEGND
VDD level to POR rising edge
(VMID rising)
Vpord_hi
Measured from LINEGND
0.63
0.8
1
V
VDD level to POR rising edge
(LINEVDD/AVDD rising)
Vpora_hi
Measured from LINEGND
1.44
1.8
2.18
V
VDD level to POR falling edge
(LINEVDD/AVDD falling)
Vpora_lo
Measured from LINEGND
0.96
1.46
1.97
V
158
mV
Table 5 Power on Reset
Note: All values are simulated results
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DEVICE DESCRIPTION
INTRODUCTION
The WM8523 provides high fidelity, 2Vrms ground referenced stereo line output from a single supply line
with minimal external components. The integrated DC servo eliminates the requirement for external
mute circuitry by minimising DC transients at the output during power up/down. The device is well-suited
to both stereo and multi-channel systems.
The device supports all common audio sampling rates between 8kHz and 192kHz using common MCLK
fs rates. Master and slave modes are available.
The WM8523 supports both hardware and software control modes.
In hardware control mode, the digital audio interface format is switchable between 16 to 24bits LJ, RJ
and I2S. Mute and de-emphasis control pins are also available.
In software control modes the digital audio interface is highly programmable, with four control interface
addresses to allow multiple WM8523 devices to be configured independently.
SOFTWARE CONTROL INTERFACE
Software Control Mode is selected by logic 1 or 0 on the CIFMODE pin. The logic level is referenced to
the LINEVDD power domain. When software mode is selected, the associated multi-function control
pins are defined as described in Table 6.
PIN NAME
PIN NUMBER
DESCRIPTION
TSSOP
QFN
SDOUT
12
5
SDA
13
6
Serial Data Input
SCLK
14
7
Serial Data Clock
CS
¯¯
15
8
I2C Mode - Device Address[0]
SPI Mode - Chip Select
CIFMODE
16
9
Control Interface Mode
0 = I2C Mode
1 = SPI Mode
Z = Hardware Mode
I2C Mode - Device Address[1]
SPI Mode - Serial Data Output
Table 6 Software Control Pin Configuration
In software control mode, the WM8523 is controlled by writing to its control registers. Readback is
available for all registers, including device ID and power management status bits. The control interface
2
can operate as an I C or SPI control interface: register read-back is provided on the bi-directional pin
SDA in I2C mode, and on the SDOUT pin in SPI mode. The WM8523 software control interface is
supplied by the LINEVDD power domain.
The available software control interface modes are summarised as follows:

I2C mode uses pins SCLK and SDA.

SPI mode uses pins CS
¯ ¯ , SCLK and SDA and SDOUT.
I2C mode is selected by setting the CIFMODE pin to logic 0. When CIFMODE is set to logic 1, SPI mode
is selected.
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2
I C CONTROL MODE
In I2C mode, the WM8523 is a slave device on the control interface; SCLK is a clock input, while SDA is
a bi-directional data pin. To allow arbitration of multiple slaves (and/or multiple masters) on the same
interface, the WM8523 transmits logic 1 by tri-stating the SDA pin, rather than pulling it high. An external
pull-up resistor is required to pull the SDA line high so that the logic 1 can be recognised by the master.
In order to allow many devices to share a single I2C control bus, every device on the bus has a unique 7bit device address (this is not the same as the 8-bit address of each register in the WM8523). The
device address is determined by the logic level on the SDOUT and CS
¯ ¯ pins as shown in Table 7. The
LSB of the device address is the R/W
¯ ¯ bit; this bit is set to logic 1 for “Read” and logic 0 for “Write”.
SDOUT
ADDR1
CS
¯¯
ADDR0
DEVICE ADDRESS
0
0
0011 0100 (34h)
0
1
0011 0110 (36h)
1
0
0011 1100 (3Ch)
1
1
0011 1110 (3Eh)
Table 7 Control Interface Device Address Selection
The WM8523 operates as an I2C slave device only. The controller indicates the start of data transfer
with a high to low transition on SDA while SCLK remains high. This indicates that a device address,
2
register address and data will follow. All devices on the I C bus respond to the start condition and shift in
the next eight bits on SDA (7-bit device address + Read/Write bit, MSB first). If the device address
received matches the device address of the WM8523, then the WM8523 responds by pulling SDA low on
the next clock pulse (ACK). If the device address is not recognised or the R/W
¯ ¯ bit is ‘1’ when operating
in write only mode, the WM8523 returns to the idle condition and waits for a new start condition and valid
address.
If the device address matches the device address of the WM8523, the data transfer continues as
described below. The controller indicates the end of data transfer with a low to high transition on SDA
while SCLK remains high. After receiving a complete address and data sequence the WM8523 returns
to the idle state and waits for another start condition. If a start or stop condition is detected out of
sequence at any point during data transfer (i.e. SDA changes while SCLK is high), the device returns to
the idle condition.
The WM8523 supports the following read and write operations:
•
•
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The sequence of signals associated with a single register write operation is illustrated in Figure 8.
Figure 8 Control Interface I2C Register Write
The sequence of signals associated with a single register read operation is illustrated in Figure 9.
Figure 9 Control Interface I2C Register Read
Figure 10 Single Register Write to Specified Address
Figure 11 Single Register Read from Specified Address
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SPI CONTROL MODE
The WM8523 can also be controlled by writing to registers through a SPI control interface. A control
word consists of 24 bits. The first bit is the read/write bit (R/W
¯ ¯ ), which is followed by 7 address bits (A6
to A0) that determine which control register is accessed. The remaining 16 bits (B15 to B0) are data bits,
corresponding to the 16 bits in each control register.
Volume update registers R06h and R07h are unavailable in SPI control mode. To use volume update in
software control mode, I2C mode must be used.
In SPI mode, every rising edge of SCLK clocks in one data bit from the SDA pin. A rising edge on CS
¯¯
latches in a complete control word consisting of the last 24 bits.
The SPI mode write operation protocol is illustrated in Figure 12.
Figure 12 SPI Control Interface – write operation
In Write operations (R/W
¯ ¯ =0), all SDA bits are driven by the controlling device.
In Read operations (R/W
¯ ¯ =1), the SDA pin is ignored following receipt of the valid register address. The
data bits are output by the WM8523 on the SDOUT pin.
The SPI mode read operation protocol is illustrated in Figure 13.
Figure 13 SPI Control Interface – read operation
REGISTER RESET
Any write to register R0 (00h) will reset the WM8523. All register bits are reset to their default values.
DEVICE ID AND REVISION
Reading from register R0 (00h) returns the device ID. Reading from register R1 returns the device
revision number.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R0
DEVICE_ID
00h
15:0
DEVICE_ID
[15:0]
10000101
00100011
Device ID
A read of this register will return the device
ID, 0x8523.
R1
REVISION
01h
2:0
CHIP_REV
[2:0]
N/A
Device Revision
A read of this register will return the device
revision number. This number is
sequentially incremented if the device
design is updated.
Table 8 Device ID and Revision Number
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DIGITAL AUDIO INTERFACE
The digital audio interface is used for inputting audio data to the WM8523. The digital audio interface
uses three pins:
•
DACDAT: DAC data input
•
LRCLK: Left/Right data alignment clock
•
BCLK: Bit clock, for synchronisation
In software control mode, all interface data formats and modes of operation can be selected.
In
hardware control mode, only a subset of formats and modes are supported – see the Hardware Interface
Control section on page 32 for details.
MASTER AND SLAVE MODE OPERATION
The WM8523 digital audio interface can operate as a master or as a slave as shown in Figure 14 and
Figure 15.
Figure 14 Slave Mode
Figure 15 Master Mode
INTERFACE FORMATS
The WM8523 supports five different audio data formats:
•
Left justified
•
Right justified
•
I 2S
•
DSP Mode A
•
DSP Mode B
PCM operation is supported using the DSP mode. All seven of these modes are MSB first. They are
described in Audio Data Formats on page 22. Refer to the “Electrical Characteristics” section for timing
information. Refer to Table 10 for interface control format register settings.
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AUDIO DATA FORMATS
In Right Justified mode, the LSB is available on the last rising edge of BCLK before a LRCLK transition.
All other bits are transmitted before (MSB first). Depending on word length, BCLK frequency and sample
rate, there may be unused BCLK cycles after each LRCLK transition.
Figure 16 Right Justified Audio Interface (assuming n-bit word length)
In Left Justified mode, the MSB is available on the first rising edge of BCLK following a LRCLK transition.
The other bits up to the LSB are then transmitted in order. Depending on word length, BCLK frequency
and sample rate, there may be unused BCLK cycles before each LRCLK transition.
Figure 17 Left Justified Audio Interface (assuming n-bit word length)
In I2S mode, the MSB is available on the second rising edge of BCLK following a LRCLK transition. The
other bits up to the LSB are then transmitted in order. Depending on word length, BCLK frequency and
sample rate, there may be unused BCLK cycles between the LSB of one sample and the MSB of the
next.
2
Figure 18 I S Justified Audio Interface (assuming n-bit word length)
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In DSP mode, the left channel MSB is available on either the 1st (mode B) or 2nd (mode A) rising edge of
BCLK (selectable by AIF_LRCLK_INV) following a rising edge of LRCLK. Right channel data
immediately follows left channel data. Depending on word length, BCLK frequency and sample rate,
there may be unused BCLK cycles between the LSB of the right channel data and the next sample.
In device master mode, the LRCLK output will resemble the frame pulse shown in Figure 19 and Figure
20. In device slave mode, Figure 21 and Figure 22, it is possible to use any length of frame pulse less
than 1/fs, providing the falling edge of the frame pulse occurs greater than one BCLK period before the
rising edge of the next frame pulse.
Figure 19 DSP Mode Audio Interface (mode A, AIF_LRCLK_INV=0, Master)
Figure 20 DSP Mode Audio Interface (mode B, AIF_LRCLK_INV=1, Master)
Figure 21 DSP Mode Audio Interface (mode A, AIF_LRCLK_INV=0, Slave)
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Figure 22 DSP Mode Audio Interface (mode B, AIF_LRCLK_INV=1, Slave)
DIGITAL AUDIO INTERFACE CONTROL
The control of the audio interface in software mode is achieved by register write. Dynamically changing
the audio data format may cause erroneous operation and is not recommended.
Digital audio data is transferred to the WM8523 via the digital audio interface. The DAC operates in
master or slave mode.
The DAC audio interface requires left/right frame clock (LRCLK) and bit clock (BCLK). These can be
supplied externally (slave mode) or they can be generated internally (master mode). Selection of master
and slave mode is achieved by setting AIF_MSTR bit in Register 3.
The frequency of LRCLK in master mode is dependent upon the DAC master clock frequency and the
AIF_SR[2:0] bits. The frequency of BCLK in master mode can be selected by AIF_BCLKDIV[2:0]. In
slave mode, the MCLK to LRCLK ratio can be auto-detected or set manually using the AIF_SR[2:0] bits.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R3
AIF_CTRL1
03h
7
AIF_MSTR
0
Master/Slave Select
0 = Slave
1 = Master
R4
AIF_CTRL2
04h
2:0
AIF_SR[2:0
000
MCLK:LRCLK Ratio
000 = Auto detect
001 = 128fs
010 = 192fs
011 = 256fs
100 = 384fs
101 = 512fs
110 = 768fs
111 = 1152fs
5:3
AIF_BCLK
DIV[2:0]
000
BCLK Divider Control (Master Mode)
000 = MCLK/4
001 = MCLK/8
010 = 32fs
011 = 64fs
100 = 128fs
101 - 111 reserved
Table 9 DAC Clocking Mode Control
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Interface timing is such that the input data and left/right clock are sampled on the rising edge of BCLK.
By setting the appropriate BCLK and LRCLK polarity bits, the WM8523 DAC can sample data on the
opposite clock edges.
The control of audio interface formats and clock polarities is summarised in Table 10.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R3
AIF_CTRL1
03h
1:0
AIF_FMT
10
Audio Data Interface Format
00 = Right justified
01 = Left justified
10 = I2S format
11 = DSP mode
2
Reserved
0
Reserved
4:3
AIF_WL
10
Audio Data Word Length
00 = 16 bits
01 = 20 bits
10 = 24 bits
11 = 32 bits
5
AIF_BCLK_
INV
0
BCLK Inversion Control
Slave mode:
0 = use rising edge
1 = use falling edge
Master mode:
0 = BCLK normal
1 = BCLK inverted
6
AIF_LRCLK
_INV
0
LRCLK Inversion Control
0 = normal polarity
1 = inverted polarity
When AIF_FMT[2:0]=011 (DSP Mode):
0 = mode A (2nd clock)
1 = mode B (1st clock)
Table 10 Audio Interface Control
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DIGITAL AUDIO DATA SAMPLING RATES
The external master clock is applied directly to the MCLK input pin. In a system where there are a
number of possible sources for the reference clock, it is recommended that the clock source with the
lowest jitter be used for the master clock to optimise the performance of the WM8523.
In slave mode the WM8523 has a detection circuit that automatically determines the relationship
between the master clock frequency (MCLK) and the sampling rate (LRCLK), to within ±32 system clock
periods. The MCLK must be synchronised with the LRCLK, although the device is tolerant of phase
variations or jitter on the MCLK.
If the device is configured in slave mode using auto-detect or in hardware mode, and during sample rate
change the ratio between MCLK and LRCLK varies more than once within 1026 LRCLK periods, then it is
recommended that the device be taken into the standby state or the off state before the sample rate
change and held in standby until the sample rate change is complete. This will ensure correct operation
of the detection circuit on the return to the enabled state. For details on the standby state, please refer to
the Software Control Interface (software mode, page 17) and Power Up and Down Control In Hardware
Mode section of the datasheet (hardware mode, on page 33).
The DAC supports MCLK to LRCLK ratios of 128fs to 1152fs and sampling rates of 8kHz to 192kHz,
provided the internal signal processing of the DAC is programmed to operate at the correct rate.
Table 11 shows typical master clock frequencies and sampling rates supported by the WM8523 DAC.
MASTER CLOCK FREQUENCY (MHz)
SAMPLING
RATE LRCLK
128fs
192fs
256fs
384fs
512fs
768fs
8kHz
Unavailable
Unavailable
2.048
3.072
4.096
6.144
1152fs
9.216
32kHz
Unavailable
Unavailable
8.192
12.288
16.384
24.576
36.864
44.1kHz
Unavailable
Unavailable
11.2896
16.9344
22.5792
33.8688
Unavailable
48kHz
Unavailable
Unavailable
12.288
18.432
24.576
36.864
Unavailable
88.2kHz
11.2896
16.9344
22.5792
33.8688
Unavailable
Unavailable
Unavailable
Unavailable
96kHz
12.288
18.432
24.576
36.864
Unavailable
Unavailable
176.4kHz
22.5792
33.8688
Unavailable
Unavailable
Unavailable
Unavailable
Unavailable
192kHz
24.576
36.864
Unavailable
Unavailable
Unavailable
Unavailable
Unavailable
Table 11 MCLK Frequencies and Audio Sample Rates
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DAC FEATURES
SYSTEM ENABLE
The WM8523 includes a number of enable and disable mechanisms to allow the device to be powered
on and off in a pop-free manner. The SYS_ENA[1:0] control bits enable the DAC and analogue paths.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
R2
PSCTRL1
02h
1:0
SYS_
ENA[1:0]
00
DESCRIPTION
System Power Control
00 = Off
01 = Power down
10 = Power up and mute
11 = Power up and unmute
Table 12 System Enable Control
Note: MCLK must be present at all times when using the SYS_ENA[1:0] bits. If MCLK is stopped at any
point the device will power down to the ‘off’ state, but all register settings will remain. Restarting MCLK
will start the device internal power sequence and the device will return to the power state set by the
SYS_ENA[1:0] bits.
The power up and power down sequences are summarised in Figure 23. There is no requirement to
manually cycle the device through the sequence via register writes, as the device will always
automatically step through each stage in the sequence.
Power Up
When SYS_ENA[1:0]=00, the internal clocks are stopped and all analogue and digital blocks are
disabled for maximum power saving. The device starts up in this state in software mode. Setting
SYS_ENA[1:0]=01 enables the internal charge pump and required control circuitry, but the signal path
remains powered down. When SYS_ENA[1:0]=10 all blocks are powered up sequentially and full system
configuration is achieved. Once this is complete, the device is ready to pass audio but is muted. Setting
SYS_ENA[1:0]=11 releases the mute and audio playback begins.
Power Down
When SYS_ENA[1:0]=11 the device is powered up and passing audio. Changing SYS_ENA[1:0]=10
applies a digital softmute to the output. Setting SYS_ENA[1:0]=01 sequentially powers down all circuit
blocks but leaves the charge pump and required control circuitry enabled. This can be considered the
low-power standby state. Finally, setting SYS_ENA[1:0]=00 will disable all circuit blocks including the
charge pump, and full system initialisation will be required to restart the device.
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Figure 23 SYS_ENA[1:0] Power Up and Down Sequences
DIGITAL VOLUME CONTROL
The WM8523 DAC includes digital volume control, allowing the digital gain to be adjusted between
−100dB and +12dB in 0.25dB steps. Volume update bits allow the user to write both left and right
channel volume changes before the volume is updated. Digital volume control is only available in I2C
mode.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
R6
DAC_GAINL
06h
8:0
DACL
_VOL[8:0]
110001000
R7
DAC_GAINR
07h
8:0
DACR
_VOL[8:0]
R6
DAC_GAINL
06h
9
DACL_VU
0
R7
DAC_GAINR
07h
9
DACR_VU
0
DESCRIPTION
DAC Digital Volume
0 0000 0000 = −100dB
0 0000 0001 = −99.75dB
0 0000 0010 = −99.5dB
…0.25dB steps
1 1001 0000 = 0dB
…0.25dB steps
1 1011 1110 = +11.75dB
1 11XX XXXX = +12dB
DAC Digital Volume Update
0 = Latch DAC volume setting into
Register Map but do not update volume
1 = Latch DAC volume setting into
Register Map and update left and right
channels simultaneously
Table 13 DAC Digital Volume Control
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VOLUME CHANGE MODES
Volume can be adjusted by step change (either using zero cross or not) or by soft ramp. The volume
change mode is controlled by the DAC_VOL_DOWN_RAMP and DAC_VOL_UP_RAMP bits in R5:
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R5
DAC_CTRL3
05h
0
DAC_VOL
_DOWN_
RAMP
1
DAC Digital Volume Decrease Control
0 = apply volume decreases instantly (step)
1 = ramp volume decreases
1
DAC_VOL
_UP_
RAMP
0
DAC Digital Volume Increase Control
0 = apply volume increases instantly (step)
1 = ramp volume increases
Table 14 Volume Ramp Control
Figure 24 illustrates the effect of the volume ramp:
Figure 24 Volume Ramp Functionality
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Ramp Volume Changes
If ramp volume changes are selected, the ramp rate is dependent upon the sampling rate. The ramp
rates for common audio sample rates are shown in Table 15.
SAMPLE RATE FOR DAC (kHz)
GAIN RAMP RATE
8
(ms/dB)
1
32
0.25
44.1
0.18
48
0.17
88.2
0.1
96
0.08
176.4
0.05
192
0.04
Table 15 Volume Ramp Rate
For example, when using a sample rate of 48kHz, the time taken for a volume change from an initial
setting of 0dB to -20dB is calculated as follows:
Volume Change (dB) x Volume Ramp Rate (ms/dB) = 20 x 0.17 = 3.4ms
Zero cross is not used when ramping. The volume level in the DAC is set by the user in 0.25dB
increments, but during the volume ramp increments of 0.125dB are actually used. This step size is
inaudible and means there is no requirement to wait until a zero crossing occurs. Another benefit of not
using zero cross when ramping is that predictable ramp times are produced – there is no signal
dependency on the ramp time.
Step Volume Changes and Zero Cross
The step volume control includes optional zero cross functionality. When zero cross is enabled, by
setting DAC_ZCEN=1, volume changes are not applied until the signal crosses zero so no discontinuity
is seen in the output signal. Zero cross helps to prevent pop and click noise when changing volume
settings and is therefore recommended if using step volume changes.
The zero cross function includes a timeout which forces volume changes if a zero cross event does not
occur. The timeout period is 14400 samples, equivalent to 300ms at 48kHz sample rate.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
R5
DAC_CTRL3
05h
4
DAC_
ZCEN
0
DESCRIPTION
Zero Cross Enable
0 = Do not use zero cross
1 = Use zero cross
Table 16 Zero Cross Control
Table 17 gives a summary of the volume mode settings and their effect.
DAC_VOL_
UP_RAMP
DAC_VOL_
DOWN_RAMP
DAC_ZCEN
VOLUME CHANGE
UP
VOLUME CHANGE
DOWN
Step, no zero cross
0
0
0
Step, no zero cross
0
1
0
Step, no zero cross
Ramp
1
0
0
Ramp
Step, no zero cross
1
1
0
Ramp
Ramp
0
0
1
Step, use zero cross
Step, use zero cross
0
1
1
Step, use zero cross
Ramp
1
0
1
Ramp
Step, use zero cross
1
1
1
Ramp
Ramp
Table 17 Volume Change Summary
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MUTE
A digital mute can be applied to left and right channels independently.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R5
DAC_CTRL3
05h
2
DACL_
MUTE
0
Left DAC Mute
0 = Normal operation
1 = Mute
R5
DAC_CTRL3
05h
3
DACR_
MUTE
0
Right DAC Mute
0 = Normal operation
1 = Mute
Table 18 DAC Mute Control
The DAC mute function in software mode is controlled by the register settings DAC_VOL_UP_RAMP,
DAC_VOL_DOWN_RAMP and DAC_ZCEN as described in Table 17.
DIGITAL MONOMIX CONTROL
The DAC can be set to output a range of mono and stereo options using DAC_OP_MUX[1:0].
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
R4
AIF_CTRL2
04h
7:6
DAC_OP_
MUX[1:0]
00
DESCRIPTION
DAC Digital Monomix
00 = Stereo (Normal Operation)
01 = Mono (Left data to DACR)
10 = Mono (Right data to DACL)
11 = Digital Monomix, (L+R)/2
Table 19 Digital Monomix Control
DE-EMPHASIS
A digital de-emphasis filter may be applied to the DAC output when the sampling frequency is 44.1kHz.
Operation at 48kHz and 32kHz is also possible, but with an increase in the error from the ideal response.
Details of the de-emphasis filter characteristic for 32kHz, 44.1kHz and 48kHz can be seen in Figure 31 to
Figure 36.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
R3
AIF_CTRL1
03h
6
DAC
_DEEMP
0
DESCRIPTION
DAC De-emphasis
0 = No de-emphasis
1 = Apply de-emphasis
Table 20 De-emphasis Control
ZERO DETECT
The infinite zero detect allows the user to select the number of zero samples received before the ZFLAG
pin is asserted high, as described in Table 21.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
R8
ZERO_DETECT
08h
0
ZD_
COUNT
0
DESCRIPTION
Zero Detect Count Control
0 = 1024
1 = 2048
Table 21 Zero Detect Control
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HARDWARE CONTROL INTERFACE
The WM8523 can be controlled in hardware mode or in software modes. In hardware mode, the device
is configured according to logic levels applied to hardware pins.
Hardware control mode is selected by leaving CIFMODE pin open-circuit (high-impedance). When
hardware mode is selected, the associated multi-function control pins are defined as described in Table
22.
PIN NAME
PIN NAME
PIN NUMBER
DESCRIPTION
TSSOP
QFN
ZFLAG
7
24
Zero Flag Output
0 = Normal operation
1 = Infinite zero detect is triggered or mute is applied
DEEMPH
12
5
De-emphasis Filter Select
0 = Filter disabled
1 = Filter enabled
AIFMODE0
13
6
AIFMODE1
14
7
AIFMODE1
0
0
1
1
MUTE
¯¯¯¯¯
15
8
Mute Control
0 = Mute
1 = Normal operation
CIFMODE
16
9
Control Interface Mode
0 = I2C Mode
1 = SPI Mode
Z = Hardware Mode
AIFMODE0
0
1
0
1
FORMAT
24-bit Left Justified
24-bit I2S
16-bit Right Justified
24-bit Right Justified
Table 22 Hardware Control Pin Configuration
DE-EMPHASIS
A digital de-emphasis filter may be applied to the DAC output when the sampling frequency is 44.1kHz.
Operation at 48kHz and 32kHz is also possible, but with an increase in the error from the ideal response.
Details of the de-emphasis filter characteristic for 32kHz, 44.1kHz and 48kHz can be seen in Figure 31 to
Figure 36.
MUTE
In hardware mode, the MUTE
¯ ¯ ¯ ¯ ¯ pin controls the DAC mute to both left and right channels. When the mute
is asserted a softmute is applied to ramp the signal down, with the ramp rate related to the sample rate
as defined in Table 15 on page 30. Once mute is achieved, the ZFLAG is asserted. When the mute is
de-asserted the signal returns to full scale in one step and the ZFLAG is de-asserted.
ZERO DETECT
The zero detect function in hardware mode will assert the ZFLAG pin high when 1024 zero count
samples are input to the digital audio interface. Additionally, the ZFLAG is asserted when the device is
muted using the MUTE
¯ ¯ ¯ ¯ ¯ pin and also until the device comes out of reset.
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POWER UP AND DOWN CONTROL IN HARDWARE MODE
In hardware mode the MCLK, BCLK and MUTE
¯ ¯ ¯ ¯ ¯ pins are monitored to control how the device powers up
or down, and this is summarised in Figure 25 below.
Figure 25 Hardware Power Sequence Diagram
Off to Enable
To power up the device to enabled, start MCLK and BCLK and set MUTE
¯ ¯ ¯ ¯ ¯ = 1.
Off to Standby
To power up the device to standby, start MCLK and BCLK and set MUTE
¯ ¯ ¯ ¯ ¯ = 0. Once the device is in
standby mode, BCLK can be disabled and the device will remain in standby mode.
Standby to Enable
To transition from the standby state to the enabled state, set the MUTE
¯ ¯ ¯ ¯ ¯ pin to logic 1 and start BCLK.
Enable to Standby
To power down to a standby state leaving the charge pump running, either set the MUTE
¯ ¯ ¯ ¯ ¯ pin to logic 0 or
stop BCLK. MCLK must continue to run in these situations. The device will automatically mute and
power down quietly in either case.
Note: It is recommended that the device is placed in standby mode before sample rate change if the sample rate changes more than once
in 1026 LRCLK periods, as detailed in Digital Audio Data Sampling Rates on page 26.
Enable to Off
To power down the device completely, stop MCLK at any time. It is recommended that the device is
placed into standby mode as described above before stopping MCLK to allow a quiet shutdown.
For the timing of the off state to enabled state transition (power on to audio out timing), and the enabled
state to standby state transition (the shutdown timing), please refer to WTN0302.
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POWER DOMAINS
Figure 26 Power Domain Diagram
Power Domain
Name
Blocks Using
This Domain
Domain Description
3.3V ± 10%
AVDD
Line Driver
DAC
DC Servo
Analogue Supply
3.3V ± 10%
LINEVDD
Charge Pump
Digital LDO
Digital Pad buffers
Analogue Supply
DAC Power Supplies
Internally Generated Power Supplies and References
1.65V ± 10%
VMID
DAC, LDO
Ext decoupled resistor string
-3.3V ± 10%
CPVOUTN
Line Driver
Charge pump generated voltage
Table 23 Power Domains
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REGISTER MAP
The complete register map is shown below. The detailed description can be found in the relevant text of the device description. The WM8523 can be configured using the Control Interface. All
unused bits should be set to '0' and access to unlisted registers should be avoided.
REG
NAME
R0 (0h)
DEVICE_ID /
SW RESET
R1 (1h)
REVISION
0
0
0
0
0
0
0
0
0
0
0
0
0
R2 (2h)
PSCTRL1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
SYS_ENA[1:0]
0000h
R3 (3h)
AIF_CTRL1
0
0
0
0
0
0
0
DAC_
AIF_
DEEMP
MSTR
AIF_WL[1:0]
0
AIF_FMT[1:0]
1812h
R4 (4h)
AIF_CTRL2
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
DAC_CTRL3
0
0
0
0
0
0
R6 (6h)
DAC_GAINL
0
0
0
0
0
0
R7 (7h)
DAC_GAINR
0
0
0
0
0
0
R8 (8h)
ZERO_DETECT
0
0
0
0
0
0
0
0
AIF_
AIF_
LRCLK_
BCLK_
INV
INV
DAC_OP_MUX[1:0]
0
0
0
VU
DACR_
VU
0
0
0
0
DAC_ZC
0000h
CHIP_REV[2:0]
AIF_BCLKDIV[2:0]
DACL_
0
DEFAULT
8523h
CHIP_ID[15:0]
0000h
AIF_SR[2:0]
DAC_
R5 (5h)
0
DAC_
DACR_
DACL_
VOL_
VOL_
MUTE
MUTE
UP_
DOWN_
RAMP
RAMP
0001h
DACL_VOL[8:0]
0190h
DACR_VOL[8:0]
0190h
0
0
0
0
ZD_
COUNT
0000h
Table 24 Register Map
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PD, Rev 4.1, August 2011
35
WM8523
Production Data
REGISTER BITS BY ADDRESS
REGISTER
ADDRESS
BIT
LABEL
R0 (00h)
DEVICE_ID/
SW RESET
15:0
CHIP_ID[15:0]
DEFAULT
DESCRIPTION
REFER TO
1000_0101_0010_0011 Read this register to obtain Device ID in hex
Write any value to this register to reset all
register values to default.
Page 20
Register 00h DEVICE_ID / SW RESET
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
R1 (01h)
REVISION
2:0
CHIP_REV[2:0]
000
DESCRIPTION
REFER TO
Device Revision Number
This number is incrementally updated each time the
silicon is revised.
Page 20
Register 01h REVISION
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
R2 (02h)
PSCTRL1
1:0
SYS_ENA[1:0]
00
DESCRIPTION
System Power Control
00 = Off
01 = Power down
10 = Power up to mute
11 = Power up to unmute
REFER TO
Page 27
Register 02h PSCTRL1
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WM8523
Production Data
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R3 (03h)
AIF_CTRL1
8
DAC_DEEMP
0
DAC De-emphasis Control
0 = No de-emphasis
1 = De-emphasis enabled
Page 31
7
AIF_MSTR
0
Master/Slave Select
0 = Slave mode
1 = Master mode
Page 24
6
AIF_LRCLK_
INV
0
LRCLK Inversion Control
0 = Normal polarity
1 = Inverted polarity
When AIF_FMT[2:0]=011 (DSP Mode):
0 = Mode A (2nd clock)
1 = Mode B (1st clock)
Page 24
5
AIF_BCLK_INV
0
BCLK Inversion Control
Slave mode:
0 = Use rising edge
1 = Use falling edge
Master mode:
0 = BCLK normal
1 = BCLK inverted
Page 24
4:3
AIF_WL[1:0]
10
Audio Data Word Length
00 = 16 bits
01 = 20 bits
10 = 24 bits
11 = 32 bits
Page 24
2
Reserved
0
Reserved
2:0
AIF_FMT[1:0]
10
Audio Data Interface Format
00 = Right justified
01 = Left justified
2
10 = I S format
11 = DSP mode
REFER TO
Page 24
Register 03h AIF_CTRL1
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WM8523
Production Data
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
R4 (04h)
AIF_CTRL2
7:6
DAC_OP_
MUX[1:0]
00
Digital Monomix Control
00 = Stereo (normal operation)
01 = Mono (Left data to DACR)
10 = Mono (Right data to DACL)
11 = Digital monomix, (L+R)/2
Page 31
5:3
AIF_
BCLKDIV[2:0]
000
BCLK Divider Control (Master Mode)
000 = MCLK/4
001 = MCLK/8
010 = 32fs
011 = 64fs
100 = 128fs
101 - 111 reserved
Page 24
2:0
AIF_SR[2:0]
000
MCLK:LRCLK Ratio
000 = Auto detect
001 = 128fs
010 = 192fs
011 = 256fs
100 = 384fs
101 = 512fs
110 = 768fs
111 = 1152fs
Page 24
Register 04h AIF_CTRL2
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
R5 (05h)
DAC_CTRL3
4
DAC_ZC
0
Zero Cross Enable
0 = Do not use zero cross
1 = Use zero cross
Page 28
3
DACR_MUTE
0
Right DAC Mute
0 = Normal operation
1 = Mute
Page 31
2
DACL_MUTE
0
Left DAC Mute
0 = Normal operation
1 = Mute
Page 31
1
DAC_VOL_
UP_RAMP
0
DAC Digital Volume Increase Control
0 = Apply volume increases instantly (step)
1 = Ramp volume increases
Page 29
0
DAC_VOL_
DOWN_RAMP
1
DAC Digital Volume Decrease Control
0 = Apply volume decreases instantly (step)
1 = Ramp volume decreases
Page 29
Register 05h DAC_CTRL3
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WM8523
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REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
R6 (06h)
DAC_GAINL
9
DACL_VU
0
Left DAC Digital Volume Update
0 = Latch Left DAC volume setting into register map
but do not update volume
1 = Latch Left DAC volume setting into register map
and update left and right channels simultaneously
Page 28
8:0
DACL_VOL[8:0]
1_1001_0000 Left DAC Digital Volume Control
0 0000 0000 = -100dB
0 0000 0001 = -99.75dB
0 0000 0010 = -99.5dB
…0.25dB steps
1 1001 0000 = 0dB
…0.25dB steps
1 1011 1110 = +11.75dB
1 11XX XXXX = +12dB
Page 28
Register 06h DAC_GAINL
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
R7 (07h)
DAC_GAIN
R
9
DACR_VU
0
8:0
DESCRIPTION
REFER TO
Right DAC Digital Volume Update
0 = Latch Right DAC volume setting into register
map but do not update volume
1 = Latch Right DAC volume setting into register
map and update left and right channels
simultaneously
DACR_VOL[8:0] 1_1001_0000 Right DAC Digital Volume Control
0 0000 0000 = -100dB
0 0000 0001 = -99.75dB
0 0000 0010 = -99.5dB
…0.25dB steps
1 1001 0000 = 0dB
…0.25dB steps
1 1011 1110 = +11.75dB
1 11XX XXXX = +12dB
Page 28
Page 28
Register 07h DAC_GAINR
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
R8 (08h)
ZERO_
DETECT
0
ZD_COUNT[1:0]
0
DESCRIPTION
Zero Detect Count Control
0 = 1024
1 = 2048
REFER
TO
Page 31
Register 08h ZERO_DETECT
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WM8523
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DIGITAL FILTER CHARACTERISTICS
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
DAC Filter – 256fs to 1152fs
Passband
± 0.1dB
0.454fs
Passband Ripple
0.1
Stopband
Stopband attenuation
dB
0.546fs
f > 0.546fs
-50
Group Delay
dB
14.5
Fs
DAC Filter – 128fs and 192fs
Passband
± 0.1dB
0.247fs
Passband Ripple
0.1
Stopband
Stopband attenuation
Group Delay
dB
0.753fs
f > 0.753fs
-50
dB
6.5
Fs
TERMINOLOGY
1.
Stop Band Attenuation (dB) – the degree to which the frequency spectrum is attenuated (outside audio band)
2.
Pass-band Ripple – any variation of the frequency response in the pass-band region
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WM8523
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DAC FILTER RESPONSES
0.2
0
0.15
0.1
Response (dB)
Response (dB)
-20
-40
-60
0.05
0
-0.05
-0.1
-80
-0.15
-100
-0.2
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
Frequency (Fs)
-120
0
0.5
1
1.5
2
2.5
3
Frequency (Fs)
Figure 27 DAC Digital Filter Frequency Response
– 256fs to 1152fs Clock Modes
Figure 28 DAC Digital Filter Ripple – 256fs to 1152fs
Clock Modes
0.2
0
0
Response (dB)
Response (dB)
-20
-40
-60
-0.2
-0.4
-0.6
-0.8
-80
-1
0
-100
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
Frequency (Fs)
Frequency (Fs)
Figure 29 DAC Digital Filter Frequency Response
– 128fs and 192fs Clock Modes
w
Figure 30 DAC Digital Filter Ripple – 128fs to 192fs Clock
Modes
PD, Rev 4.1, August 2011
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WM8523
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DIGITAL DE-EMPHASIS CHARACTERISTICS
0
1
0.5
-2
Response (dB)
Response (dB)
0
-4
-6
-0.5
-1
-1.5
-2
-8
-2.5
-10
-3
0
2
4
6
8
10
Frequency (kHz)
12
14
16
0
2
4
6
8
10
Frequency (kHz)
Figure 31 De-Emphasis Frequency Response (32kHz)
Figure 32 De-Emphasis Error (32kHz)
Figure 33 De-Emphasis Frequency Response (44.1kHz)
Figure 34 De-Emphasis Error (44.1kHz)
0
12
14
16
1
0.8
-2
0.6
Response (dB)
Response (dB)
0.4
-4
-6
0.2
0
-0.2
-0.4
-8
-0.6
-0.8
-10
-1
0
5
10
15
Frequency (kHz)
20
Figure 35 De-Emphasis Frequency Response (48kHz)
w
0
5
10
15
Frequency (kHz)
20
Figure 36 De-Emphasis Error (48kHz)
PD, Rev 4.1, August 2011
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WM8523
Production Data
APPLICATIONS INFORMATION
RECOMMENDED EXTERNAL COMPONENTS – 20-LEAD TSSOP
Figure 37 Recommended External Components
Notes:
1.
Wolfson recommend using a single, common ground plane. Where this is not possible, care should be taken to
optimise split ground configuration for audio performance.
2.
Charge Pump fly-back capacitor C5 should be placed as close to WM8523 as possible, followed by Charge Pump
decoupling capacitor C1, then LINEVDD and VMID decoupling capacitors. See Recommended PCB Layout on p44.
3.
Capacitor types should be chosen carefully. Capacitors with very low ESR are recommended for optimum
performance.
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WM8523
Production Data
LINEGND
CPCB
CPVOUTN
VMID
AVDD
CPCA
AGND
LINEVDD
RECOMMENDED PCB LAYOUT – 20-LEAD TSSOP
Figure 38 Recommended PCB Layout
Notes:
1.
C5 should be placed as close to WM8523 as possible, with minimal track lengths to reduce inductance and maximise
performance of the charge pump. Vias should be avoided in the tracking to C5.
2.
C1 is then next most important and should also be placed as close as possible to the WM8523. Again, minimise
track lengths and avoid vias to reduce parasitic inductance.
3.
C2 and C4 are then next most important, and lastly C3.
4.
The WM8523 evaluation board, details available at www.wolfsonmicro.com, shows an example of good component
placement and layout to maximise performance with a minimal BOM.
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WM8523
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RECOMMENDED EXTERNAL COMPONENTS – 24-LEAD QFN
Figure 39 Recommended External Components
Notes:
1.
Wolfson recommend using a single, common ground plane. Where this is not possible, care should be taken to
optimise split ground configuration for audio performance.
2.
Charge Pump fly-back capacitor C5 should be placed as close to WM8523 as possible, followed by Charge Pump
decoupling capacitor C1, then LINEVDD and VMID decoupling capacitors. See Recommended PCB Layout on p44.
3.
Capacitor types should be chosen carefully. Capacitors with very low ESR are recommended for optimum
performance.
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45
WM8523
Production Data
LINEGND
CPCB
CPVOUTN
AGND
VMID
CPCA
AGND
LINEVDD
RECOMMENDED PCB LAYOUT – 24-LEAD QFN
Figure 40 Recommended PCB Layout
Notes:
1.
C5 should be placed as close to WM8523 as possible, with minimal track lengths to reduce inductance and maximise
performance of the charge pump. Vias should be avoided in the tracking to C5.
2.
C1 is then next most important and should also be placed as close as possible to the WM8523. Again, minimise
track lengths and avoid vias to reduce parasitic inductance.
3.
C2 and C4 are then next most important, and lastly C3.
4.
The WM8523 evaluation board, details available at www.wolfsonmicro.com, shows an example of good component
placement and layout to maximise performance with a minimal BOM.
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WM8523
Production Data
RECOMMENDED ANALOGUE LOW PASS FILTER
Figure 41 Recommended Analogue Low Pass Filter (one channel shown)
An external single-pole RC filter is recommended if the device is driving a wideband
amplifier. Other filter architectures may provide equally good results.
The filter shown in Figure 41 has a -3dB cut-off at 105.26kHz and a droop of 0.15dB at
20kHz. The typical output from the WM8523 is 2.1Vrms – when a 10kΩ load is placed at the
output of this recommended filter the amplitude across this load is 1.99Vrms.
RELEVANT APPLICATION NOTES
The following application notes, available from www.wolfsonmicro.com, may provide
additional guidance for use of the WM8523.
DEVICE PERFORMANCE:
WAN0129 – Decoupling and Layout Methodology for Wolfson DACs, ADCs and CODECs
WAN0144 – Using Wolfson Audio DACs and CODECs with Noisy Supplies
WTN0302 - WM8524 Recommended Power Sequence and Timing (for hardware mode)
GENERAL:
WAN0108 – Moisture Sensitivity Classification and Plastic IC Packaging
WAN0109 – ESD Damage in Integrated Circuits: Causes and Prevention
WAN0158 – Lead-Free Solder Profiles for Lead-Free Components
WAN0161 – Electronic End-Product Design for ESD
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WM8523
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PACKAGE DIMENSIONS – 20-LEAD TSSOP
DT: 20 PIN TSSOP (6.5 x 4.4 x 1.0 mm)
b
DM008.D
e
20
11
E1
E
GAUGE
PLANE
1
D
θ
10
0.25
c
A A2
L
A1
-C0.1 C
SEATING PLANE
Symbols
A
A1
A2
b
c
D
e
E
E1
L
θ
MIN
----0.05
0.80
0.19
0.09
6.40
4.30
0.45
0o
REF:
Dimensions
(mm)
NOM
--------1.00
--------6.50
0.65 BSC
6.4 BSC
4.40
0.60
-----
MAX
1.20
0.15
1.05
0.30
0.20
6.60
4.50
0.75
8o
JEDEC.95, MO-153
NOTES:
A. ALL LINEAR DIMENSIONS ARE IN MILLIMETERS.
B. THIS DRAWING IS SUBJECT TO CHANGE WITHOUT NOTICE.
C. BODY DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSION, NOT TO EXCEED 0.25MM.
D. MEETS JEDEC.95 MO-153, VARIATION = AC. REFER TO THIS SPECIFICATION FOR FURTHER DETAILS.
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WM8523
Production Data
PACKAGE DIMENSIONS – 24-LEAD QFN
FL: 24 PIN QFN PLASTIC PACKAGE 4 X 4 X 0.75 mm BODY, 0.50 mm LEAD PITCH
DM061.A
DETAIL 1
D
D2
19
24
1
18
EXPOSED
GROUND 6
PADDLE
A
INDEX AREA
(D/2 X E/2)
4
E2
E
SEE DETAIL 2
13
6
2X
12
7
b
e
1
bbb M C A B
2X
aaa C
aaa C
TOP VIEW
BOTTOM VIEW
DETAIL 1
A
0.08 C
L
45
degrees
A1
SIDE VIEW
C
DETAIL 2
5
0.3mm
DETAIL 3
SEATING PLANE
Datum
1
ccc C
A3
EXPOSED
GROUND
PADDLE
Terminal
Tip
e/2
e
R
A3
G
b
Exposed lead
DETAIL 3
Symbols
A
A1
A3
b
D
D2
E
E2
e
G
L
aaa
bbb
ccc
REF:
2.65
NOM
0.75
0.02
0.203 REF
0.25
4.00 BSC
2.70
4.00 BSC
2.70
0.35
0.50 BSC
0.625
0.40
MIN
0.70
0
0.20
2.65
MAX
0.80
0.05
NOTE
0.30
1
2.75
2
2.75
2
0.45
Tolerances of Form and Position
0.15
0.10
0.10
JEDEC, MO-220
NOTES:
1. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.15 mm AND 0.30 mm FROM TERMINAL TIP.
2. FALLS WITHIN JEDEC, MO-220.
3. ALL DIMENSIONS ARE IN MILLIMETRES.
4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL CONFORM TO JEDEC 95-1 SPP-002.
5. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS.
6. REFER TO APPLICATIONS NOTE WAN_0118 FOR FURTHER INFORMATION REGARDING PCB FOOTPRINTS AND QFN PACKAGE SOLDERING.
7. DEPENDING ON THE METHOD OF LEAD TERMINATION AT THE EDGE OF THE PACKAGE, PULL BACK (L1) MAY BE PRESENT.
8. THIS DRAWING IS SUBJECT TO CHANGE WITHOUT NOTICE.
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IMPORTANT NOTICE
Wolfson Microelectronics plc (“Wolfson”) products and services are sold subject to Wolfson’s terms and conditions of sale,
delivery and payment supplied at the time of order acknowledgement.
Wolfson warrants performance of its products to the specifications in effect at the date of shipment. Wolfson reserves the
right to make changes to its products and specifications or to discontinue any product or service without notice. Customers
should therefore obtain the latest version of relevant information from Wolfson to verify that the information is current.
Testing and other quality control techniques are utilised to the extent Wolfson deems necessary to support its warranty.
Specific testing of all parameters of each device is not necessarily performed unless required by law or regulation.
In order to minimise risks associated with customer applications, the customer must use adequate design and operating
safeguards to minimise inherent or procedural hazards. Wolfson is not liable for applications assistance or customer
product design. The customer is solely responsible for its selection and use of Wolfson products. Wolfson is not liable for
such selection or use nor for use of any circuitry other than circuitry entirely embodied in a Wolfson product.
Wolfson’s products are not intended for use in life support systems, appliances, nuclear systems or systems where
malfunction can reasonably be expected to result in personal injury, death or severe property or environmental damage.
Any use of products by the customer for such purposes is at the customer’s own risk.
Wolfson does not grant any licence (express or implied) under any patent right, copyright, mask work right or other
intellectual property right of Wolfson covering or relating to any combination, machine, or process in which its products or
services might be or are used. Any provision or publication of any third party’s products or services does not constitute
Wolfson’s approval, licence, warranty or endorsement thereof. Any third party trade marks contained in this document
belong to the respective third party owner.
Reproduction of information from Wolfson datasheets is permissible only if reproduction is without alteration and is
accompanied by all associated copyright, proprietary and other notices (including this notice) and conditions. Wolfson is
not liable for any unauthorised alteration of such information or for any reliance placed thereon.
Any representations made, warranties given, and/or liabilities accepted by any person which differ from those contained in
this datasheet or in Wolfson’s standard terms and conditions of sale, delivery and payment are made, given and/or
accepted at that person’s own risk. Wolfson is not liable for any such representations, warranties or liabilities or for any
reliance placed thereon by any person.
ADDRESS
Wolfson Microelectronics plc
Westfield House
26 Westfield Road
Edinburgh
EH11 2QB
Tel :: +44 (0)131 272 7000
Fax :: +44 (0)131 272 7001
Email :: [email protected]
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Production Data
REVISION HISTORY
DATE
REV
ORIGINATOR
23/08/10
4.1
BT
Added minimum A-weighted SNR limit of 100dB
9
BT
Changed Group delay of 256/128fs filters from 10fs to 14.5fs and 6.5fs
40
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CHANGES
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51