WM8706_05 [WOLFSON]

24-bit, 192kHz Stereo DAC with Volume Control; 24位, 192kHz的立体声DAC,具有音量控制
WM8706_05
型号: WM8706_05
厂家: WOLFSON MICROELECTRONICS PLC    WOLFSON MICROELECTRONICS PLC
描述:

24-bit, 192kHz Stereo DAC with Volume Control
24位, 192kHz的立体声DAC,具有音量控制

文件: 总26页 (文件大小:290K)
中文:  中文翻译
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WM8706  
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24-bit, 192kHz Stereo DAC with Volume Control  
DESCRIPTION  
FEATURES  
Stereo DAC  
The WM8706 is a high performance stereo DAC designed  
for audio applications such as DVD, home theatre systems,  
and digital TV. The WM8706 supports data input word  
lengths from 16 to 32-bits and sampling rates up to 192kHz.  
The WM8706 can implement 2 channels at 192kHz for high-  
end DVD-Audio. The WM8706 consists of a serial interface  
port, digital interpolation filters, multi-bit sigma delta  
modulators and stereo DAC in a small 28-lead SSOP  
package. The WM8706 also includes a digitally controllable  
mute and attenuate function on each channel.  
Audio Performance  
-
-
106dB SNR (‘A’ weighted @ 48kHz) DAC  
-97dB THD  
DAC Sampling Frequency: 8kHz – 192kHz  
3-Wire Serial Control Interface or Hardware Control  
Programmable Audio Data Interface Modes  
-
I2S, Left, Right Justified, DSP  
16/20/24/32 bit Word Lengths  
-
The WM8706 supports a variety of connection schemes for  
audio DAC control. The MPU serial port provides access to  
a wide range of features including on-chip mute, attenuation  
and phase reversal. A hardware controllable interface is  
also available. It is pin-compatible with the WM8716  
provided the oscillator circuit on WM8716 is not required in  
the application.  
Independent Digital Volume Control on Each Channel with  
127.5dB Range in 0.5dB Steps  
3.0V – 5.5V Supply Operation  
28-Lead SSOP Package  
Exceeds Dolby Class A Performance Requirements  
APPLICATIONS  
The WM8706 is an ideal device to interface to AC-3,  
DTS, and MPEG audio decoders for surround sound  
applications, or for use in DVD players supporting DVD-A.  
DVD-Audio and DVD ‘Universal’ Players  
Home theatre systems  
Digital TV  
Digital broadcast receivers  
BLOCK DIAGRAM  
MLIIS  
MCDM1 MDDM0 MUTEB CSBIWO ZERO  
MODE  
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WM8706  
CONTROL INTERFACE  
SIGMA  
DELTA  
MODULATOR  
LOW  
PASS  
FILTER  
RIGHT  
DAC  
MUTE/  
ATTEN  
VOUTR  
VOUTL  
BCKIN  
LRCIN  
DIN  
SERIAL  
INTERFACE  
DIGITAL FILTERS  
SIGMA  
DELTA  
MODULATOR  
LOW  
PASS  
FILTER  
LEFT  
DAC  
MUTE/  
ATTEN  
VMID  
XTI  
DGND  
AVDD DVDD  
VREFP VREFN AGND  
Production Data, July 2005, Rev 4.1  
WOLFSON MICROELECTRONICS plc  
Copyright 2005 Wolfson Microelectronics plc  
To receive regular email updates, sign up at http://www.wolfsonmicro.com/enews/  
WM8706  
Production Data  
TABLE OF CONTENTS  
DESCRIPTION ............................................................................................................1  
FEATURES..................................................................................................................1  
APPLICATIONS ..........................................................................................................1  
BLOCK DIAGRAM ......................................................................................................1  
PIN CONFIGURATION................................................................................................3  
ORDERING INFORMATION .......................................................................................3  
PIN DESCRIPTION .....................................................................................................4  
ABSOLUTE MAXIMUM RATINGS..............................................................................5  
DC ELECTRICAL CHARACTERISTICS .....................................................................6  
ELECTRICAL CHARACTERISTICS ...........................................................................6  
TERMINOLOGY................................................................................................................. 7  
MASTER CLOCK TIMING.................................................................................................. 8  
DIGITAL AUDIO INTERFACE............................................................................................ 8  
MPU INTERFACE TIMING................................................................................................. 9  
DEVICE DESCRIPTION............................................................................................10  
INTRODUCTION...............................................................................................................10  
CLOCKING SCHEMES .....................................................................................................10  
DIGITAL AUDIO INTERFACE...........................................................................................10  
AUDIO DATA SAMPLING RATES.....................................................................................13  
HARDWARE CONTROL MODES .....................................................................................13  
SOFTWARE CONTROL INTERFACE...............................................................................15  
REGISTER MAP ...............................................................................................................16  
ATTENUATION CONTROL...............................................................................................18  
DIGITAL FILTER CHARACTERISTICS....................................................................21  
DAC FILTER RESPONSES...............................................................................................21  
DIGITAL DE-EMPHASIS CHARACTERISTICS........................................................22  
RECOMMENDED EXTERNAL COMPONENTS .......................................................23  
RECOMMENDED EXTERNAL COMPONENT VALUES ...................................................23  
RECOMMENDED ANALOGUE LOW PASS FILTER (OPTIONAL) .........................24  
PACKAGE DIMENSIONS .........................................................................................25  
IMPORTANT NOTICE...............................................................................................26  
ADDRESS: ........................................................................................................................26  
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PIN CONFIGURATION  
28  
27  
26  
25  
24  
23  
22  
21  
20  
19  
18  
17  
16  
15  
1
MLIIS  
LRCIN  
DIN  
2
MCDM1  
MDDM0  
3
BCKIN  
NC  
4
MUTEB  
MODE  
CSBIWO  
NC  
5
XTI  
6
NC  
7
DGND  
DVDD  
NC  
8
ZERO  
VREFP  
VREFN  
VMID  
NC  
9
10  
11  
12  
13  
14  
NC  
NC  
NC  
VOUTL  
AVDD  
VOUTR  
AGND  
ORDERING INFORMATION  
DEVICE  
TEMPERATURE  
RANGE  
PACKAGE  
MOISTURE  
PEAK SOLDERING  
TEMPERATURE  
SENSITIVITY LEVEL  
WM8706SEDS  
-25 to +85oC  
MSL 1  
260oC  
28-lead SSOP  
(lead free)  
WM8706SEDS/R  
-25 to +85oC  
MSL 1  
260oC  
28-lead SSOP  
(lead free, tape and  
reel)  
Note:  
Reel quantity = 2,000  
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PIN DESCRIPTION  
PIN  
1
NAME  
LRCIN  
DIN  
TYPE  
Digital Input  
Digital Input  
Digital Input  
NC  
DESCRIPTION  
DAC Sample Rate Clock Input  
2
Serial Audio Data Input  
Audio Data Bit Clock Input.  
No internal connection  
3
BCKIN  
4
5
ZERO  
Digital Output (Open Drain) Infinite ZERO Detect Flag (L=IZD detected, H=IZD not detected)  
6
NC  
Supply  
No Internal Connection  
7
DGND  
DVDD  
Digital Ground Supply  
8
Supply  
Digital Positive Supply  
9
NC  
No Internal Connection  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
NC  
No Internal Connection  
NC  
No Internal Connection  
NC  
No Internal Connection  
VOUTR  
AGND  
AVDD  
Analogue Output  
Supply  
Right Channel DAC Output  
Analogue Ground Supply  
Supply  
Analogue Positive Supply  
VOUTL  
Analogue Output  
NC  
Left Channel DAC Output  
No Internal Connection  
VMID  
VREFN  
VREFP  
ZERO  
Analogue Output  
Supply  
Mid Rail Decoupling Point  
DAC Negative Reference – normally AGND, must not be below AGND  
DAC Positive Reference – normally AVDD, must not be above AVDD  
Infinite Zero Detect Flag  
Supply  
Digital Output  
NC  
No Internal Connection  
CSBIWO  
Digital Input  
Software Mode: 3-Wire Serial Control Chip Select  
Hardware Mode: Input Word Length, Pull Up  
Control Mode Selection (Low = Hardware, High = Software), Pull Down  
24  
25  
MODE  
Digital Input  
MUTEB  
Digital Bi-directional  
Mute Control (L = Mute on, H = Mute off, Z = Automute Enabled), Pull  
Up  
26  
27  
28  
MDDM0  
MCDM1  
MLIIS  
Digital Bi-directional  
Digital Input  
Software Mode: 3-Wire Serial Control Data Input:  
Hardware Mode: De-Emphasis  
Software Mode: 3-Wire Serial Control Clock Input  
Hardware Mode: De-Emphasis, Pull Down  
Software Mode 3-Wire Serial Control Load Input  
Hardware Mode: Input Data Format Selection, Pull Up  
Digital Input  
Note:  
Digital input pins have Schmitt trigger input buffers.  
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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  
MIN  
-0.3V  
MAX  
+7V  
Digital supply voltage  
Analogue supply voltage  
Voltage range digital inputs  
Voltage range analogue inputs  
Master Clock Frequency (XTI)  
Operating temperature range, TA  
Storage temperature  
-0.3V  
+7V  
DGND -0.3V  
AGND -0.3V  
DVDD +0.3V  
AVDD +0.3V  
50MHz  
-25°C  
-65°C  
+85°C  
+150°C  
Note:  
Analogue and digital grounds must always be within 0.3V of each other.  
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DC ELECTRICAL CHARACTERISTICS  
PARAMETER  
SYMBOL  
DVDD  
TEST CONDITIONS  
MIN  
3.0  
TYP  
MAX  
UNIT  
V
Digital supply range  
Analogue supply range  
Ground  
5.5  
5.5  
AVDD  
3.0  
V
AGND, DGND  
0
0
V
Difference DGND to AGND  
Analogue supply current  
Digital supply current  
Analogue supply current  
Digital supply current  
-0.3  
+0.3  
V
AVDD = 5V  
DVDD = 5V  
AVDD = 3.3V  
DVDD = 3.3V  
19  
8
mA  
mA  
mA  
mA  
18  
4
ELECTRICAL CHARACTERISTICS  
Test Conditions  
AVDD, DVDD = 5V, AGND, DGND = 0V, TA = +25oC, fs = 48kHz, XTI = 256fs unless otherwise stated.  
PARAMETER  
SYMBOL  
TEST CONDITIONS  
MIN  
TYP  
MAX  
0.8  
UNIT  
Digital Logic Levels (TTL Levels)  
Input LOW level  
VIL  
VIH  
V
V
V
V
Input HIGH level  
2.0  
Output LOW  
VOL  
VOH  
I
OL = 1mA  
AGND + 0.3V  
Output HIGH  
I
OH = 1mA  
AVDD - 0.3V  
(VREFP -  
Analogue Reference Levels  
Reference voltage  
VMID  
(VREFP -  
(VREFP -  
V
VREFN)/2 - VREFN)/2 VREFN)2 +  
50mV  
50mV  
Potential divider resistance  
RVMID  
10k  
DAC Output (Load = 10K . 50pF)  
0dBFs Full scale output voltage  
At DAC outputs  
1.1 x  
AVDD/5  
106  
Vrms  
dB  
SNR (Note 1,2,3)  
SNR (Note 1,2,3)  
SNR (Note 1,2,3)  
SNR (Note 1,2,3)  
A-weighted,  
@ fs = 48kHz  
A-weighted  
@ fs = 96kHz  
A-weighted  
100  
106  
106  
102  
dB  
dB  
@ fs = 192kHz  
A-weighted,  
dB  
@ fs = 48kHz  
AVDD, DVDD = 3.3V  
A-weighted  
@ fs = 96kHz  
AVDD, DVDD = 3.3V  
SNR (Note 1,2,3)  
SNR (Note 1,2,3)  
102  
dB  
Non ‘A’ weighted @ fs  
= 48kHz  
103  
dB  
THD (Note 1,2,3)  
1kHz, 0dBfs  
-97  
106  
100  
dB  
dB  
dB  
THD+N (Dynamic range, Note 2)  
DAC channel separation  
1kHz, -60dBfs  
100  
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Test Conditions  
AVDD, DVDD = 5V, AGND, DGND = 0V, TA = +25oC, fs = 48kHz, XTI = 256fs unless otherwise stated.  
PARAMETER  
SYMBOL  
TEST CONDITIONS  
MIN  
TYP  
MAX  
UNIT  
Analogue Output Levels  
Output level  
Load = 10k , 0dBFS  
1.1  
VRMS  
VRMS  
Load = 10k , 0dBFS,  
0.726  
(AVDD = 3.3V)  
Gain mismatch  
channel-to-channel  
1
1
%FSR  
kΩ  
Minimum resistance load  
To midrail or a.c.  
coupled  
To midrail or a.c.  
coupled  
600  
(AVDD = 3.3V)  
Maximum capacitance load  
Output d.c. level  
5V or 3.3V  
100  
pF  
V
(VREFP -  
VREFN)/2  
Power On Reset (POR)  
POR threshold  
2.4  
V
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.  
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MASTER CLOCK TIMING  
tXTIL  
XTI  
tXTIH  
tXTIY  
Figure 1 Master Clock Timing Requirements  
Test Conditions  
AVDD, DVDD = 5V, AGND, DGND = 0V, TA = +25oC, fs = 48kHz, XTI = 256fs unless otherwise stated.  
PARAMETER  
SYMBOL  
TEST CONDITIONS  
MIN  
TYP  
MAX  
UNIT  
Master Clock Timing Information  
XTI Master clock pulse width high  
XTI Master clock pulse width low  
XTI Master clock cycle time  
XTI Duty cycle  
tXTIH  
tXTIL  
tXTIY  
13  
13  
ns  
ns  
ns  
26  
40:60  
60:40  
DIGITAL AUDIO INTERFACE  
tBCH  
tBCL  
BCKIN  
LRCIN  
DIN  
tBCY  
tLRSU  
tDS  
tLRH  
tDH  
Figure 2 Digital Audio Data Timing  
Test Conditions  
AVDD, DVDD = 5V, AGND, DGND = 0V, TA = +25oC, fs = 48kHz, XTI = 256fs unless otherwise stated.  
PARAMETER  
SYMBOL  
TEST CONDITIONS  
MIN  
TYP  
MAX  
UNIT  
Audio Data Input Timing Information  
BCKIN cycle time  
tBCY  
tBCH  
tBCL  
40  
16  
16  
8
ns  
ns  
ns  
ns  
BCKIN pulse width high  
BCKIN pulse width low  
LRCIN set-up time to  
BCKIN rising edge  
tLRSU  
LRCIN hold time from  
BCKIN rising edge  
tLRH  
tDS  
8
8
8
ns  
ns  
ns  
DIN set-up time to BCKIN  
rising edge  
DIN hold time from BCKIN  
rising edge  
tDH  
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MPU INTERFACE TIMING  
CSBIWO  
MLIIS  
tCSSU  
tCSSH  
tCSL  
tCSH  
tSCY  
tCSS  
tSCS  
tSCH  
tSCL  
MCDM1  
MDDM0  
LSB  
tDSU  
tDHO  
Figure 3 Program Register Input Timing - 3-Wire Serial Control Mode  
Test Conditions  
AVDD, DVDD = 5V, AGND, DGND = 0V, TA = +25oC, fs = 48kHz, XTI = 256fs unless otherwise stated.  
PARAMETER  
SYMBOL  
TEST CONDITIONS  
MIN  
TYP  
MAX  
UNIT  
Program Register Input Information  
MCDM1 rising edge to MLIIS  
rising edge  
tSCS  
40  
ns  
MCDM1 pulse cycle time  
MCDM1 pulse width low  
MCDM1 pulse width high  
MDDM0 to MCDM1 set-up time  
MCDM1 to MDDM0 hold time  
MLIIS pulse width low  
tSCY  
tSCL  
80  
20  
20  
20  
20  
20  
20  
20  
20  
20  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
Ns  
ns  
tSCH  
tDSU  
tDHO  
tCSL  
MLIIS pulse width high  
tCSH  
tCSS  
tCSSU  
tCSSH  
MLIIS rising to SCLK rising  
CSBIWO to MLIIS set-up time  
MLIIS to CSBIWO hold time  
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DEVICE DESCRIPTION  
INTRODUCTION  
The WM8706 is a high performance DAC designed for digital consumer audio applications. Its  
range of features make it ideally suited for use in DVD players, AV receivers and other high end  
consumer audio equipment.  
The WM8706 is a complete 2-channel stereo audio digital-to-analogue converter, including  
digital interpolation filter, multi-bit sigma delta with dither, and switched capacitor multi-bit  
stereo DAC and output smoothing filters. The WM8706 includes an on-board digital volume  
control, configurable digital audio interface and a 3 wire MPU control interface. It is fully  
compatible and an ideal partner for a range of industry standard microprocessors, controllers  
and DSPs.  
Control of internal functionality of the device is by either hardware control (pin programmed) or  
software control (3-wire serial control interface). The MODE pin selects between hardware and  
software control. The software control interface may be asynchronous to the audio data  
interface. Control data will be re-synchronised to the audio processing internally.  
Operation using master clocks of 256fs, 384fs, 512fs or 768fs is provided, selection between  
clock rates being automatically controlled in hardware mode, or serial controlled when in  
software mode. Sample rates (fs) from less than 8ks/s to 96ks/s are allowed, provided the  
appropriate master clock is input. Support is also provided for up to 192ks/s using a master  
clock of 128fs or 192fs.  
The audio data interface supports right, left and I2S (Philips left justified, one bit delayed)  
interface formats along with a highly flexible DSP serial port interface. When in hardware mode,  
the three serial interface pins become control pins to allow selection of input data format type  
(I2S or right justified), input word length (16, 20, or 24-bit) and de-emphasis functions.  
The device is packaged in a small 28-pin SSOP and is a pin-compatible alternative to the  
WM8716.  
CLOCKING SCHEMES  
In a typical digital audio system there is only one central clock source producing a reference  
clock to which all audio data processing is synchronised. This clock is often referred to as the  
audio system’s Master Clock. The external master system clock can be applied directly through  
the XTI input pin with no software configuration necessary for sample rate selection.  
Note that on the WM8706, XTI is used to derive clocks for the DAC path. The DAC path  
consists of DAC sampling clock, DAC digital filter clock and DAC digital audio interface timing.  
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 to optimise the performance  
of the DAC.  
DIGITAL AUDIO INTERFACE  
Audio data is applied to the internal DAC filters via the Digital Audio Interface. 5 popular  
interface formats are supported:  
Left Justified mode  
Right Justified mode  
I2S mode  
DSP Early mode  
DSP Late mode  
All 5 formats send the MSB first and support word lengths of 16, 20, 24 and 32 bits. The  
exception is that 32 bit data is not supported in right justified mode. DIN and LRCIN are  
sampled on the rising, or falling edge of BCKIN depending on the format selected.  
In left justified, right justified and I2S modes, the digital audio interface receives data on the DIN  
input. Audio Data is time multiplexed with LRCIN indicating whether the left or right channel is  
present. LRCIN is also used as a timing reference to indicate the beginning or end of the data  
words.  
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In left justified, right justified and I2S modes, the minimum number of BCKINs per LRCIN period  
is 2 times the selected word length. LRCIN must be high for a minimum of word length BCKINs  
and low for a minimum of word length BCKINs. Any mark to space ratio on LRCIN is  
acceptable provided the above requirements are met. The WM8706 will automatically detect  
when data with a LRCIN period of exactly 32 is sent, and select 16 bit mode - overriding any  
previously programmed word length. Word length will revert to the previously programmed  
value when a LRCIN period other than 32 is detected. (see Figure 4, Figure 5 and Figure 6).  
In DSP early or DSP late mode, the data is time multiplexed onto DIN. LRCIN is used as a  
frame sync signal to identify the MSB of the first word. The minimum number of BCKINs per  
LRCIN period is 2 times the selected word length. Any mark to space ratio is acceptable on  
LRCIN provided the rising edge is correctly positioned (see Figure 7 and Figure 8).  
LEFT JUSTIFIED MODE  
In left justified mode, the MSB is sampled on the first rising edge of BCKIN following a LRCIN  
transition. LRCIN is high during the left samples and low during the right samples.  
1/fs  
LEFT CHANNEL  
RIGHT CHANNEL  
LRCIN  
BCKIN  
DIN  
1
2
3
n
n-2 n-1  
1
2
3
n
n-2 n-1  
MSB  
LSB  
MSB  
LSB  
Figure 4 Left Justified Mode Timing Diagram  
RIGHT JUSTIFIED MODE  
In right justified mode, the LSB is sampled on the rising edge of BCKIN preceding a LRCIN  
transition. LRCIN is high during the left samples and low during the right samples.  
1/fs  
LEFT CHANNEL  
RIGHT CHANNEL  
LRCIN  
BCKIN  
DIN  
1
2
3
n
1
2
3
n
n-2 n-1  
n-2 n-1  
MSB  
LSB  
MSB  
LSB  
Figure 5 Right Justified Mode Timing Diagram  
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I2S MODE  
In I2S mode, the MSB is sampled on the second rising edge of BCKIN following a LRCIN  
transition. LRCIN is low during the left samples and high during the right samples.  
1/fs  
LEFT CHANNEL  
RIGHT CHANNEL  
LRCIN  
BCKIN  
1 BCKIN  
1 BCKIN  
DIN  
1
2
3
n
1
2
3
n
n-2 n-1  
n-2 n-1  
LSB  
LSB  
MSB  
MSB  
Figure 6 I2S Mode Timing Diagram  
DSP EARLY MODE  
In DSP early mode, the first bit is sampled on the BCKIN rising edge following the one which  
detects a low to high transition on LRCIN. No BCKIN edges are allowed between the data  
words. The word order is DIN left, DIN right.  
1 BCKIN  
1 BCKIN  
1/fs  
LRCIN  
BCKIN  
LEFT CHANNEL  
RIGHT CHANNEL  
NO VALID DATA  
DIN  
1
2
n
1
2
n
n-1  
n-1  
MSB  
LSB  
Input Word Length (IWO)  
Figure 7 DSP Early Mode Timing Diagram  
DSP LATE MODE  
In DSP late mode, the first bit is sampled on the BCKIN rising edge which detects a low to high  
transition on LRCIN. No BCKIN edges are allowed between the data words. The word order is  
DIN left, DIN right.  
1/fs  
LRCIN  
BCKIN  
LEFT CHANNEL  
RIGHT CHANNEL  
NO VALID DATA  
DIN  
1
2
n
1
2
n
1
n-1  
n-1  
MSB  
LSB  
Input Word Length (IWO)  
Figure 8 DSP Late Mode Timing Diagram  
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AUDIO DATA SAMPLING RATES  
The master clock for WM8706 supports audio sampling rates from 128fs to 768fs, where fs is  
the audio sampling frequency (LRCIN) typically 32kHz, 44.1kHz, 48kHz, 96kHz or 192kHz. The  
master clock is used to operate the digital filters and the noise shaping circuits.  
The WM8706 has a master clock detection circuit that automatically determines the relation  
between the master clock frequency and the sampling rate (to within +/- 32 master clocks). If  
there is a greater than 8 clocks error, the interface shuts down the DAC and mutes the output.  
The master clock should be synchronised with LRCIN, although the WM8706 is tolerant of  
phase differences or jitter on this clock.  
SAMPLING  
RATE  
MASTER CLOCK FREQUENCY (MHZ) (XTI)  
128fs  
192fs  
256fs  
384fs  
512fs  
768fs  
(LRCIN)  
32kHz  
44.1kHz  
48kHz  
4.096  
5.6448  
6.114  
6.144  
8.467  
8.192  
11.2896  
12.288  
24.576  
12.288  
16.9340  
18.432  
36.864  
16.384  
22.5792  
24.576  
24.576  
33.8688  
36.864  
9.216  
18.432  
96kHz  
12.288  
Unavailable Unavailable  
192kHz  
24.576  
36.864  
Unavailable Unavailable Unavailable Unavailable  
Table 1 Typical Relationships Between System Frequency and Sampling Rates.  
HARDWARE CONTROL MODES  
When the MODE pin is held low, the following hardware modes of operation are available.  
MUTE AND AUTOMUTE OPERATION  
In both hardware and software modes, pin 25 (MUTEB) controls selection of MUTE directly,  
and can be used to enable and disable the automute function. Automute is enabled by leaving  
MUTEB pin floating, it is disabled by applying a signal to the pin. When left floating this pin  
becomes an output and indicates infinite ZERO detect (IZD), see also pin 5 (ZERO). The  
status of IZD controls the selection of MUTE when automute is enabled. When IZD is detected  
MUTE is enabled and when IZD is not detected MUTE is disabled.  
MUTEB PIN  
DESCRIPTION  
0
1
Mute DAC channels  
Normal Operation  
Floating  
Enable IZD, MUTEB becomes an output to indicate when IZD occurs.  
Table 2 Mute and Automute Control  
ZERO PIN  
DESCRIPTION  
0
1
Indicates Infinite Zero detected from the digital input.  
Indicates Infinite Zero not detected from the digital input.  
Table 3 Zero Pin Output  
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Figure 9 shows the application and release of MUTE whilst a full amplitude sinusoid is being  
played at 48kHz sampling rate. When MUTE (lower trace) is asserted, the output (upper trace)  
begins to decay exponentially from the DC level of the last input sample. The output will decay  
towards VMID with a time constant of approximately 64 input samples. When MUTE is de-  
asserted, the output will restart almost immediately from the current input sample.  
1.5  
1
0.5  
0
-0.5  
-1  
-1.5  
-2  
-2.5  
0
0.001  
0.002  
0.003  
0.004  
0.005  
0.006  
Time(s)  
Figure 9 Application and Release of Soft Mute  
The MUTEB pin is an input to select mute or not mute. MUTEB is active low; taking the pin low  
causes the filters to soft mute, ramping down the audio signal over a few milliseconds. Taking  
MUTEB high again allows data into the filter.  
The automute function detects a series of zero value audio samples of 1024 samples long  
being applied to both channels. After such an event,  
a latch is set whose output  
(AUTOMUTED) is wire OR’ed through a 10kohm resistor to the MUTEB pin. Thus if the  
MUTEB pin is not being driven, the automute function will assert mute.  
If MUTEB is tied high, AUTOMUTE is overridden and will not mute unless the IZD register bit is  
set. If MUTEB is driven from a bi-directional source, then both MUTE and automute functions  
are available. If MUTEB is not driven, AUTOMUTED appears as a weak output (10k source  
impedance) so can be used to drive external mute circuits. Automute will be removed as soon  
as any channel receives a non-zero input.  
A diagram showing how the various Mute modes interact is shown below in Figure 10.  
IZD (Register Bit)  
AUTOMUTED  
(Internal Signal)  
10k  
SOFTMUTE  
(Internal  
Signal)  
MUTEB  
PIN  
MUT (Register Bit)  
Figure 10 Selection Logic for MUTE Modes  
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INPUT FORMAT SELECTION  
In hardware mode, MLIIS (pin 28) and CSBIWO (pin 23) become input controls for selection of  
input data format type and input data word length.  
MLIIS  
CSBIWO  
INPUT DATA MODE  
24-bit right justified**  
20-bit right justified  
16-bit I2S  
0
0
0
1
0
1
1
1
24-bit I2S  
Table 4 Input Format Selection  
Note:  
In 24 bit I2S mode, any width of 24 bits or less is supported provided that LRCIN is high for a  
minimum of 24 BCKINs and low for a minimum of 24 BCKINs.  
** This mode differs from the WM8716 which does 16-bit right justified in this mode. The  
previous mode is still available by using exactly 32 BCKIN per LRCIN cycle, 16 for left and  
right. This mode is automatically detected within the hardware and overrides the data width  
specified but not the format.  
DE-EMPHASIS CONTROL  
In hardware mode, MCDM1 (pin 27) and MDDM0 (pin 26) become input controls for selection  
of de-emphasis filtering to be applied.  
MCDM1  
MDDM0  
DE-EMPHASIS**  
Off  
0
0
0
1
0
1
48kHz  
1
44.1kHz  
32kHz  
1
Table 5 De-emphasis Control  
Note:  
** The actual de-emphasis within the WM8706 is the same for all data rates. This differs from  
WM8716 which has a different response for each sample rate.  
SOFTWARE CONTROL INTERFACE  
SELECTION OF CONTROL MODE  
The WM8706 may be programmed to operate in hardware or software control modes. This is  
achieved by setting the state of the MODE pin.  
MODE  
INTERFACE FORMAT  
Hardware Control Mode  
Software Control Mode  
0
1
Table 6 Control Interface Mode Selection  
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3-WIRE (SPI COMPATIBLE) SERIAL CONTROL MODE  
The WM8706 can be controlled using a 3-wire serial interface. MDDM0 is used for the program  
data, MCDM1 is used to clock in the program data and MLIIS is used to latch in the program  
data. The 3-wire interface protocol is shown in Figure 11.  
MLIIS  
MCDM1  
B15  
B14  
B13  
B12  
B11  
B10  
B9  
B8  
B7  
B6  
B5  
B4  
B3  
B2  
B1  
B0  
MDDM0  
Figure 11 3-Wire Serial Interface  
Notes:  
1. B[15:9] are Control Address Bits  
2. B[8:0] are Control Data Bits  
REGISTER MAP  
WM8706 uses a total of 4 programme registers, which are 16-bits long. These registers are all  
loaded through input pin MDDM0. After the 16 data bits are clocked in, MLIIS is used to latch in  
the data to the appropriate register. Table  
4 registers.  
7
shows the complete mapping of the  
B15  
B14  
B13  
B12  
B11  
B10  
B9  
0
B8  
B7  
B6  
LAT6  
RAT6  
0
B5  
LAT5  
RAT5  
IW2  
B4  
B3  
LAT3  
RAT3  
IW0  
0
B2  
LAT2  
RAT2  
B1  
LAT1  
RAT1  
B0  
LAT0  
RAT0  
M0  
M1  
M2  
M3  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
UPDATEL LAT7  
UPDATER RAT7  
LAT4  
RAT4  
IW1  
0
1
0
0
0
0
PWRDN DEEMPH MUT  
I2S  
0
1
IZD  
SF1  
SF0  
BCP  
REV  
ATC  
LRP  
ADDRESS  
DATA  
Table 7 Mapping of Program Registers  
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REGISTER  
ADDRESS  
A2, A1, A0  
000  
BITS  
LABEL  
DEFAULT  
DESCRIPTION  
[7:0]  
8
LAT[7:0]  
11111111 (0dB)  
0
Attenuation data for left channel in 0.5dB steps.  
Attenuation data load control for left channel.  
A2, A1, A0  
UPDATEL  
DACL  
Attenuation  
0: Store DACL in intermediate latch (no change to output)  
1: Store DACL and update attenuation on all channels.  
Attenuation data for right channel in 0.5dB steps.  
Attenuation data load control for right channel.  
0: Store DACR in intermediate latch (no change to output)  
1: Store DACR and update attenuation on all channels.  
Left and right DACs soft mute control.  
0: No mute  
001  
[7:0]  
8
RAT[7:0] 11111111 (0dB)  
DACR  
Attenuation  
UPDATER  
0
0
0
0
010  
0
1
2
MUT  
DAC Control  
1: Mute  
DEEMPH  
PWDN  
De-emphasis control.  
0: De-emphasis off  
1: De-emphasis on  
Left and Right DACs Power-down Control  
0: All DACs running, output is active  
1: All DACs in power saving mode, output muted  
Audio data format select.  
[5:3]  
0
IW[2:0]  
I2S  
000  
0
011  
Audio data format select.  
Interface  
Control  
1
LRP  
0
Polarity select for LRCIN/DSP mode select.  
0: normal LRCIN polarity/DSP late mode  
1: inverted LRCIN polarity/DSP early mode  
2
ATC  
0
Attenuator Control.  
0: All DACs use attenuations as programmed.  
1: Right channel DACs use corresponding left DAC  
attenuations  
4
5
REV  
BCP  
0
0
Output phase reverse.  
BCKIN Polarity  
0 : normal BCKIN polarity  
1: inverted BCKIN polarity  
[7:6]  
8
SF[1:0]  
IZD  
00  
0
De-Emphasis sample rate select.  
Infinite zero detection circuit control and automute control  
0: Infinite zero detect disabled  
1: Infinite zero detect enabled  
Table 8 Register Bit Descriptions  
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ATTENUATION CONTROL  
Each DAC channel can be attenuated digitally before being applied to the digital filter. Attenuation is 0dB by default but can be  
set between 0 and 127.5dB in 0.5dB steps using the 8 Attenuation control bits. All attenuation registers are double latched  
allowing new values to be pre-latched to both channels before being updated synchronously. Setting the UPDATE bit on any  
attenuation write will cause all pre-latched values to be immediately applied to the DAC channels.  
REGISTER  
ADDRESS  
BIT  
LABEL  
DEFAULT  
DESCRIPTION  
A2, A1, A0  
000  
7:0  
8
LAT[7:0]  
11111111  
(0dB)  
Attenuation data for Left channel DACL in 0.5dB steps.  
DACL  
Attenuation  
UPDATEL  
0
Controls simultaneous update of all Attenuation Latches  
0: Store DACL in intermediate latch (no change to output)  
1: Store DACL and update attenuation on all channels.  
Attenuation data for Right channel DACR in 0.5dB steps.  
001  
7:0  
8
RAT[7:0]  
11111111  
(0dB)  
DACR  
Attenuation  
UPDATER  
0
Controls simultaneous update of all Attenuation Latches  
0: Store DACR in intermediate latch (no change to output)  
1: Store DACR and update attenuation on all channels.  
Table 9 Attenuation Register Map  
Note:  
1. The UPDATE bit is not latched. If UPDATE=0, the Attenuation value will be written to the pre-latch but not applied to the  
relevant DAC. If UPDATE=1, all pre-latched values will be applied from the next input sample.  
2. Care should be used in reducing the attenuation as rapid large volume changes can introduce zipper noise.  
DAC OUTPUT ATTENUATION  
Registers LAT and RAT control the left and right channel attenuation. Table 10 shows how the  
attenuation levels are selected from the 8-bit words.  
XAT[7:0]  
ATTENUATION LEVEL  
00(hex)  
dB (mute)  
01(hex)  
127.5dB  
:
:
:
:
:
:
FE(hex)  
0.5dB  
0dB  
FF(hex)  
Table 10 Attenuation Control Levels  
MUTE MODES  
Setting the MUT register bit will apply a 'soft' mute to the input of the digital filters:  
REGISTER ADDRESS  
010  
BIT  
LABEL  
DEFAULT  
DESCRIPTION  
Soft Mute select  
0
MUT  
0
0 : Normal Operation  
DAC Control  
1: Soft mute all channels  
Table 11 Mute Control  
DE-EMPHASIS MODE  
Setting the DEEMPH register bit puts the all the digital filters into de-emphasis mode:  
REGISTER ADDRESS  
010  
BIT  
LABEL  
DEFAULT  
DESCRIPTION  
De-emphasis mode select:  
0 : De-emphasis Off  
1
DEEMPH  
0
DAC Control  
1: De-emphasis On  
Table 12 De-emphasis Control  
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POWERDOWN MODE  
Setting the PWDN register bit immediately connects all outputs to VMID and selects a low power  
mode. All trace of the previous input samples is removed, and all register settings are cleared.  
When PWDN is cleared again the first 16 input samples will be ignored as the FIR will repeat  
it's power-on initialisation sequence.  
REGISTER ADDRESS  
010  
BIT  
LABEL  
DEFAULT  
DESCRIPTION  
2
PWDN  
0
Power Down Mode Select:  
0 : Normal Mode  
DAC Control  
1: Power Down Mode  
Table 13 Powerdown Control  
DIGITAL AUDIO INTERFACE CONTROL REGISTERS  
The WM8706 has a fully featured digital audio interface that is a superset of that contained in  
the WM8716. Interface format is selected via the IW[2:0] register bits in register M2 and the I2S  
register bit in M3.  
REGISTER ADDRESS  
010  
BIT  
LABEL  
DEFAULT  
DESCRIPTION  
5:3  
IW[2:0]  
000  
Interface format Select  
DAC Control  
Table 14 Interface Format Controls  
REGISTER ADDRESS  
011  
BIT  
LABEL  
I2S  
DEFAULT  
DESCRIPTION  
0
0
Interface format Select  
Interface Control  
Table 15 Interface Format Control  
I2S  
IW2  
IW1  
IW0  
AUDIO INTERFACE DESCRIPTION **  
16 bit right justified mode  
0
0
0
0
0
0
0
0
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
20 bit right justified mode  
24 bit right justified mode  
24 bit left justified mode  
16 bit I2S mode  
24 bit I2S mode  
20 bit I2S mode  
20 bit left justified (MSB first) mode  
16 bit DSP mode  
20 bit DSP mode  
24 bit DSP mode  
32 bit DSP mode  
16 bit left justified mode  
Table 16 Audio Data Input Format  
Note:  
** In all modes, the data is signed 2's complement. The digital filters always input 24-bit data. If  
the DAC is programmed to receive 16 or 20 bit data, the WM8706 pads the unused LSBs with  
zeros. If the DAC is programmed into 32 bit mode, the 4 LSBs are ignored.  
SELECTION OF LRCIN POLARITY  
In left justified, right justified or I2S modes, the LRP register bit controls the polarity of LRCIN. If  
this bit is set high, the expected polarity of LRCIN will be the opposite of that shown in Figure 4,  
Figure 5 and Figure 6. Note that if this feature is used as a means of swapping the left and  
right channels, a 1 sample phase difference will be introduced.  
REGISTER ADDRESS  
011  
BIT  
LABEL  
DEFAULT  
DESCRIPTION  
1
LRP  
0
LRCIN Polarity (normal)  
0 : normal LRCIN polarity  
1: inverted LRCIN polarity  
Interface Control  
Table 17 LRCIN Polarity Control  
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In DSP modes, the LRCIN register bit is used to select between early and late modes:  
REGISTER ADDRESS  
011  
BIT  
LABEL  
DEFAULT  
DESCRIPTION  
1
LRP  
0
DSP Format (DSP modes)  
0 : Early DSP mode  
Interface Control  
1: Late DSP mode  
Table 18 DSP Format Control  
In DSP early mode, the first bit is sampled on the BCKIN rising edge following the one that  
detects a low to high transition on LRCIN. In DSP late mode, the first bit is sampled on the  
BCKIN edge, which detects a low to high transition on LRCIN. No BCKIN rising edges are  
allowed between the data words. The word order is DIN left, DIN right.  
ATTENUATOR CONTROL MODE  
Setting the ATC register bit causes the left channel attenuation settings to be applied to both  
left and right channel DACs from the next audio input sample. No update to the attenuation  
registers is required for ATC to take effect.  
REGISTER ADDRESS  
011  
BIT  
LABEL  
DEFAULT  
DESCRIPTION  
2
ATC  
0
Attenuate Control Mode:  
0 : Right channels use Right  
attenuation  
Interface Control  
1: Right Channels use Left  
Attenuation  
Table 19 Attenuation Control Select  
OUTPUT PHASE REVERSAL  
The REV register bit controls the phase of the output signal. Setting the REV bit causes the  
phase of the output signal to be inverted.  
REGISTER ADDRESS  
011  
BIT  
LABEL  
DEFAULT  
DESCRIPTION  
Analogue Output Phase  
0: Normal  
4
REV  
0
Interface Control  
1: Inverted  
Table 20 Output Phase Control  
BCKIN POLARITY  
By default, LRCIN and DIN are sampled on the rising edge of BCKIN and should ideally change  
on the falling edge. Data sources which change LRCIN and DIN on the rising edge of BCKIN  
can be supported by setting the BCP register bit. Setting BCP to 1 inverts the polarity of BCKIN  
to the inverse of that shown in Figure 4, Figure 5, Figure 6, Figure 7 and Figure 8.  
REGISTER ADDRESS  
011  
BIT  
LABEL  
DEFAULT  
DESCRIPTION  
BCKIN Polarity  
5
BCP  
0
0 : normal BCKIN polarity  
1: inverted BCKIN polarity  
Interface Control  
Table 21 BCKIN Polarity Control  
DE-EMPHASIS SAMPLE RATE SELECTION  
The SF[1:0] bits are used to select the de-emphasis rate.  
REGISTER ADDRESS  
0011  
BIT  
LABEL  
DEFAULT  
DESCRIPTION **  
7:6  
SF[1:0]  
00  
De-Emphasis Sample Rate Selection  
00 : De-Emphasis Off  
01: 48kHz  
Interface Control  
10: 44.1kHz  
11: 32kHz  
Table 22 De-emphasis Control  
Note:  
** There is only one internal de-emphasis mode optimised for 44.1kHz. This is in contrast to  
WM8716 which is individually optimised for each sample rate.  
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INFINITE ZERO DETECTION  
Setting the IZD register bit determines whether the device is automuted when a sequence of  
more than 1024 zeros is detected.  
REGISTER ADDRESS  
011  
BIT  
LABEL  
DEFAULT  
DESCRIPTION  
8
IZD  
0
Infinite zero detection circuit control  
and automute control  
Interface Control  
0: Infinite zero detect disabled  
1: Infinite zero detect enabled  
Table 23 IZD Control  
DIGITAL FILTER CHARACTERISTICS  
PARAMETER  
SYMBOL  
TEST CONDITIONS  
-3dB  
MIN  
TYP  
MAX  
UNIT  
Passband Edge  
Passband Ripple  
Stopband Attenuation  
0.487fs  
f < 0.444fs  
f > 0.555fs  
±0.05  
dB  
dB  
-60  
Table 24 Digital Filter Characteristics  
DAC FILTER RESPONSES  
0.2  
0.15  
0.1  
0
-20  
-40  
0.05  
0
-60  
-0.05  
-0.1  
-0.15  
-0.2  
-80  
-100  
-120  
0
0.5  
1
1.5  
2
2.5  
3
0
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 12 DAC Digital Filter Frequency Response  
- 44.1, 48 and 96kHz  
Figure 13 DAC Digital Filter Ripple - 44.1, 48 and 96kHz  
0.2  
0
-20  
-40  
-60  
-80  
0
-0.2  
-0.4  
-0.6  
-0.8  
-1  
0
0.2  
0.4  
0.6  
0.8  
1
0
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 14 DAC Digital Filter Frequency Response  
- 192kHz  
Figure 15 DAC Digital Filter Ripple - 192kHz  
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DIGITAL DE-EMPHASIS CHARACTERISTICS  
0
1
0.5  
0
-2  
-4  
-0.5  
-1  
-6  
-1.5  
-2  
-8  
-2.5  
-3  
-10  
0
2
4
6
8
10  
12  
14  
16  
0
2
4
6
8
10  
12  
14  
16  
Frequency (kHz)  
Frequency (kHz)  
Figure 16 De-Emphasis Frequency Response (32kHz)  
Figure 17 De-Emphasis Error (32kHz)  
0
0.4  
0.3  
0.2  
0.1  
0
-2  
-4  
-6  
-0.1  
-0.2  
-0.3  
-0.4  
-8  
-10  
0
5
10  
15  
20  
0
5
10  
15  
20  
Frequency (kHz)  
Frequency (kHz)  
Figure 18 De-Emphasis Frequency Response (44.1kHz)  
Figure 19 De-Emphasis Error (44.1kHz)  
0
1
0.8  
0.6  
0.4  
0.2  
0
-2  
-4  
-6  
-0.2  
-0.4  
-0.6  
-0.8  
-1  
-8  
-10  
0
5
10  
15  
20  
0
5
10  
15  
20  
Frequency (kHz)  
Frequency (kHz)  
Figure 20 De-Emphasis Frequency Response (48kHz)  
Figure 21 De-Emphasis Error (48kHz)  
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RECOMMENDED EXTERNAL COMPONENTS  
Figure 22 External Components Diagram  
RECOMMENDED EXTERNAL COMPONENT VALUES  
COMPONENT  
REFERENCE  
SUGGESTED  
VALUE  
DESCRIPTION  
C1 and C5  
C2 to C4  
C6 and C7  
C8  
10µF  
0.1µF  
10µF  
0.1µF  
10µF  
10µF  
10kΩ  
33Ω  
De-coupling for DVDD and AVDD/VREFP  
De-coupling for DVDD and AVDD/VREFP  
Output AC coupling caps to remove midrail DC level from outputs.  
Reference de-coupling capacitors for VMID pin.  
C9  
C10  
Filtering for VREFP. Omit if AVDD low noise.  
10k pull-up to DVDD.  
R1  
R2  
Filtering for VREP. Use 0if AVDD low noise.  
Table 25 External Components Description  
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RECOMMENDED ANALOGUE LOW PASS FILTER (OPTIONAL)  
4.7k  
4.7k  
+VS  
_
51  
10uF  
1.8kΩ  
7.5KΩ  
+
+
-VS  
1.0nF  
680pF  
47kΩ  
Figure 23 Recommended Low Pass Filter (Optional)  
PD Rev 4.1 July 2005  
24  
w
WM8706  
Production Data  
PACKAGE DIMENSIONS  
DS: 28 PIN SSOP (10.2 x 5.3 x 1.75 mm)  
DM007.D  
b
e
28  
15  
E1  
E
GAUGE  
PLANE  
Θ
14  
1
D
0.25  
L
c
A1  
L1  
A A2  
-C-  
0.10 C  
SEATING PLANE  
Dimensions  
(mm)  
NOM  
-----  
Symbols  
MIN  
-----  
0.05  
1.65  
0.22  
0.09  
9.90  
MAX  
A
A1  
A2  
b
c
D
e
E
E1  
L
2.0  
0.25  
1.85  
0.38  
0.25  
10.50  
-----  
1.75  
0.30  
-----  
10.20  
0.65 BSC  
7.80  
7.40  
5.00  
0.55  
8.20  
5.60  
0.95  
5.30  
0.75  
L1  
θ
0.125 REF  
0o  
4o  
8o  
JEDEC.95, MO-150  
REF:  
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 0.20MM.  
D. MEETS JEDEC.95 MO-150, VARIATION = AH. REFER TO THIS SPECIFICATION FOR FURTHER DETAILS.  
PD Rev 4.1 July 2005  
25  
w
WM8706  
Production Data  
IMPORTANT NOTICE  
Wolfson Microelectronics plc (WM) reserve the right to make changes to their products or to discontinue any product or service  
without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that  
information being relied on is current. All products are sold subject to the WM terms and conditions of sale supplied at the time  
of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability.  
WM warrants performance of its products to the specifications applicable at the time of sale in accordance with WM’s standard  
warranty. Testing and other quality control techniques are utilised to the extent WM deems necessary to support this warranty.  
Specific testing of all parameters of each device is not necessarily performed, except those mandated by government  
requirements.  
In order to minimise risks associated with customer applications, adequate design and operating safeguards must be used by  
the customer to minimise inherent or procedural hazards. Wolfson products are not authorised for use as critical components in  
life support devices or systems without the express written approval of an officer of the company. Life support devices or  
systems are devices or systems that are intended for surgical implant into the body, or support or sustain life, and whose failure  
to perform when properly used in accordance with instructions for use provided, can be reasonably expected to result in a  
significant injury to the user. A critical component is any component of a life support device or system whose failure to perform  
can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.  
WM assumes no liability for applications assistance or customer product design. WM does not warrant or represent that any  
license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property  
right of WM covering or relating to any combination, machine, or process in which such products or services might be or are  
used. WM’s publication of information regarding any third party’s products or services does not constitute WM’s approval,  
license, warranty or endorsement thereof.  
Reproduction of information from the WM web site or datasheets is permissible only if reproduction is without alteration and is  
accompanied by all associated warranties, conditions, limitations and notices. Representation or reproduction of this information  
with alteration voids all warranties provided for an associated WM product or service, is an unfair and deceptive business  
practice, and WM is not responsible nor liable for any such use.  
Resale of WM’s products or services with statements different from or beyond the parameters stated by WM for that product or  
service voids all express and any implied warranties for the associated WM product or service, is an unfair and deceptive  
business practice, and WM is not responsible nor liable for any such use.  
ADDRESS:  
Wolfson Microelectronics plc  
26 Westfield Road  
Edinburgh  
EH11 2QB  
United Kingdom  
Tel :: +44 (0)131 272 7000  
Fax :: +44 (0)131 272 7001  
Email :: sales@wolfsonmicro.com  
PD Rev 4.1 July 2005  
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