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WM8761 Evaluation Board User Handbook
INTRODUCTION
The WM8761 is a 24-bit 192kHz Stereo DAC.
This evaluation platform and documentation should be used in conjunction with the latest version of
the WM8761 datasheet. The datasheet gives device functionality information as well as timing and
data format requirements.
This evaluation platform has been designed to make it easy to gain familiarity with the WM8761 and
to allow optimum performance to be measured.
GETTING STARTED
PACKING LIST
The WM8761 Evaluation Kit contains:
1 x WM8761-EV1B Evaluation Board (Labelled WM8761_EV1)
1 x WM8761-EV1M Evaluation Board User Handbook
WM8761-EV1M
CUSTOMER REQUIREMENTS
Minimum Equipment Requires:
• D.C. Power supply of +2.7 to +5.5V (See WM8761 Datasheet for details)
• D.C. Power supply of +5V.
• D.C. Power supply of +/- 12V
Digital Input Signal Path Requires:
• Digital coaxial or optical data source
Analog Output Path Requires:
• Two Audio receivers, for LEFT and RIGHT outputs.
WOLFSON MICROELECTRONICS plc
www.wolfsonmicro.com
July 2004, Rev 1.1
Copyright 2004 Wolfson Microelectronics plc
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WM8761-EV1M
BOARD FUNCTIONALITY
This evaluation platform has been designed as a simple means of evaluating the WM8761 24-bit
192kHz Stereo DAC in a 14-pin SOIC package. It is versatile and can be configured for most
applications.
There are two options for inputting digital data into the WM8761 evaluation board. There is a coaxial
input (J12) via a standard phono connector or an optical input (U3) via a standard optical receiver
module. A direct digital input is available via one side of a 2x8 pin header (H1).
The outputs from the WM8761 are analog Left and Right stereo signals. These analog signals can
be passed through active low pass filters before being made accessible via standard phono
connectors; J10 (FILT_OUTL) and J11 (FILT_OUTR). Alternatively, non-filtered outputs can be
made accessible via standard phono connectors; J7 (VOUTL) and J15 (VOUTR).
All WM8761 device pins are accessible for easy measurement via two 1x8pin headers (J8 and J13)
running up each side of the device.
PCB MAIN CONNECTIONS
POWER SUPPLIES
CONNECTOR
REFERENCE
* Refer to the WM8761 datasheet for limitations on individual supply voltages.
CONNECTOR
TYPE
J1 4mm Panel Socket +5V 5 VDC
J2 4mm Panel Socket GND 0 VDC
J3 4mm Panel Socket DVDD 2.7 to 5.5 VDC
J4 4mm Panel Socket GND 0 VDC
J5 4mm Panel Socket -12V -12 VDC
J6 4mm Panel Socket +12V 12 VDC
SIGNAL REFERENCE VOLTAGE LEVEL *
Table 1 Power Connections
Using appropriate power leads with 4mm connectors, +2.7V to +5.5V should be applied to the DVDD
panel socket J3. 5V should be applied to panel socket J1. +12V should be applied to panel socket
J6 while -12V should be applied to panel socket J5. GND should be connected to panel sockets J2
and J4.
DIGITAL INPUTS
CONNECTOR
REFERENCE
J12 Phono Connector DIGITAL_COXIAL INPUT (SPDIF)
U3 Optical Receiver
Table 2 Digital Input Connections
CONNECTOR
TYPE
(TOSLINK)
SIGNAL REFERENCE
DIGITAL_OPTICAL INPUT (SPDIF)
ANALOG OUTPUTS
CONNECTOR
REFERENCE
J7 Phono Connector VOUTL
J15 Phono Connector VOUTR
J10 Phono Connector FILT_OUTL
J11 Phono Connector FILT_OUTR
Table 3 Digital Output Connections
CONNECTOR TYPE SIGNAL REFERENCE
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INTERFACES
WM8761-EV1M
HEADERS
SW1
01
U3
J1 J2 J3 J6
+5V
H1
J12
GND
+3V TO 5.5V
J13
DVDD
J8
1
LNK10
111
LNK2
1
J4
GND
LNK3
LNK4
LNK1
1
1
Figure 1 WM8761-EV1B Board Interfaces (Component Side)
J13 SIGNAL J8 SIGNAL
1 LRCIN 1 VDD
2 DIN 2 VOUTL
3 BCKIN 3 MUTE
4 NC 4 NC
5 CAP 5 DEEMPH
6 VOUTR 6 FORMAT
7 GND 7 MCLK
8 GND 8 GND
Table 4 WM8761 Headers
J5
-12V
LNK8
1
1
LNK12
+12V
1
J14 J9
1
J7
J9
J10
J9
J11
J15
1
2
3
4
5
6
7
8
2
1
4
3
6
5
8
7
10
9
12
11
14
13
16
15
1
2
1
2
3
KEY
H1 SIGNAL H1 SIGNAL
1 SDATA 2 DIN
3 DGND 4 DGND
5 MCK 6 MCLK
7 DGND 8 DGND
9 FSYNC 10 LRCIN
11 DGND 12 DGND
13 SCK 14 BCKIN
15 DGND 16 DGND
Table 5 Headers
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WM8761-EV1M
LINKS
SWITCHES
LINKS DESCRIPTION
LNK1 1-2 De-emphasis ON
2-3 De-emphasis OFF
LNK2 Not Populated
LNK3 1-2 Mute ON
2-3 Mute OFF
LNK4 Not Populated
LNK8 OPEN - VOUTL AC Coupled
SHORT - VOUTL DC Coupled
LNK10 1-2 I2S or DSP 'early' mode
2-3 16-Bit Right Just. or DSP 'late' mode.
LNK12 OPEN - VOUTR AC Coupled
SHORT - VOUTR DC Coupled
J9 1-2 Unfiltered VOUTL
2-3 Filtered VOUTL
J14 1-2 Unfiltered VOUTR
2-3 Filtered VOUTR
Table 6 Links
SWITCH SETTING DESCRIPTION
1 2 3 4 CS8414 Normal Audio Port Modes
0 1 0 x I2S SW1
1 0 1 x 16 Bit Right Justify
Table 7 Switches
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WM8761-EV1M
BASIC TEST SETUP
DIGITAL
AUDIO
SOURCE
The setup of the WM8761 device can be altered using the various links on the evaluation board. The
following configuration, as shown below in Figure 2, sets the digital audio interface mode to I
2
S. It
also configures de-emphasis OFF, mute OFF and AC coupled outputs with active filtering.
+5V +5V0V -12V +12V0V
J5
J4
GND
-12V
LNK3
1
LNK8
1
1
1
LNK12
+12V
1
J14 J9
1
J7
J10
J9
J9
J11
J15
SW1
01
U3
J1 J2 J3 J6
+5V
H1
J12
GND
+3V TO 5.5V
J13
DVDD
J8
1
LNK10
111
LNK2
1
LNK4
LNK1
Figure 2 Basic Test Connection Diagram
The hardware settings required for the WM8761 Evaluation board are described in the table below.
LINKS & SWITCHES DESCRIPTION
H1 Add 8 Links as shown in figure 11
SW1 Set to 0100 for I2S Mode
LNK1 Add Link 2-3
LNK3 Add Link 2-3
LNK9 Add Link 2-3
LNK10 Add Link 1-2
LNK14 Add Link 2-3
Table 8 Basic Test Evaluation Board Hardware Settings
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WM8761-EV1M
WM8761-EV1B SCHEMATIC
Figure 3 Functional Block Diagram
Figure 4 Digital Input
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WM8761-EV1M
Figure 5 Analog Output
Figure 6 WM8761
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WM8761-EV1M
Figure 7 Power
WM8761-EV1B PCB LAYOUT
Figure 8 Top Layer Silkscreen
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WM8761-EV1M
Figure 9 Top Layer
Figure 10 Bottom Layer
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WM8761-EV1M
WM8761-EV1B BILL OF MATERIAL
DESCRIPTION REFERENCE QUANTITY
Phono Socket PCB mount RED J11, J15 2
Phono Socket PCB mount YELLOW J12 1
Phono Socket PCB mount WHITE J7, J10 2
DIL Switch 4-Way Rocker SW1 1
1.32mm PCB Test Terminal BLACK TP1 – TP6 6
220pF 0805 SMD Ceramic Capacitor 50V X7R C16, C35 2
0.01uF 0805 SMD Ceramic Capacitor 50V X7R C30 1
0.1uF 0805 SMD Ceramic Capacitor 50V X7R C1 – C4, C9, C10, C19, C21, C23 – C27, C29 14
MM74HC32 Quad 2-input OR gate SO U2 1
4mm Non-Insulated Panel Socket 16A J1 – J6 6
1x2 PCB Pin Header 0.1" VERTICAL LNK8, LNK12 2
1x3 PCB Pin Header 0.1" VERTICAL J9, J14, LNK3 3
1x8 2.54mm pitch PCB Pin Header VERTICAL J8, J13 2
2x8 2.54mm pitch PCB Pin Header VERTICAL H1 1
MC33078 Low Noise Dual Op-Amp SO U6 1
0.068uF 0805 SMD Ceramic Capacitor 25V X7R C20 1
10uF 6.3 Dia 2.5 pitch Oscon Through Hole Cap. 16V 20% C5 – C8, C11, C13, C18, C32, C36 9
DS1812 5V Power-On-Reset chip SOT U1 1
680pF 0805 SMD Ceramic Capacitor 50V NPO C14, C33 2
1nF 0805 SMD Ceramic Capacitor 50V NPO C15, C34 2
0R 0805 SMD chip resistor 1% 0.1W R7, R26 2
0R 1206 Resistor on 1210 Inductor site L1 - L4 4
470R 0805 SMD chip resistor 1% 0.1W R16 1
1K8 0805 SMD chip resistor 1% 0.1W R9, R22 2
4K7 0805 SMD chip resistor 1% 0.1W R2, R3, R6, R11, R14, R18, R24 7
47K 0805 SMD chip resistor 1% 0.1W R8, R21 2
100K 0805 SMD chip resistor 1% 0.1W R1, R4, R5 3
49R9 0805 SMD chip resistor 1% 0.125W R12, R25 2
7K5 0805 SMD chip resistor 1% 0.125W R10, R23 2
47uH 1210 Surface Mount Inductor 'PA series' L5 1
Hexagonal brass M3 size spacer 20mm length P1 - P4 4
75R 0805 SMD chip resistor 1% 0.125W R20 1
Plain M3 size washer W1 - W2 4
Slotted Panhead Screw - M3 thread; 12mm long SC1 - SC4 4
CS8414 96kHz Digital Audio Receiver SO U4 1
TORX176 Digirtal Audio Optical Receiver U3 1
JSK9-16-G0 PCB 1x3 Jumper Switch 0.1" Center-off
VERTICAL
WM8761 Stereo DAC U5 1
Table 9 Bill of Material
LNK1, LNK10 2
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EVALUATION SUPPORT
The aim of this evaluation kit is to help you to become familiar with the functionality and performance
of the WM8761 Stereo DAC.
If you require more information or require technical support please contact Wolfson Microelectronics
Applications group through the following channels:
Email: apps@wolfsonmicro.com
Telephone Apps: (+44) 131 272 7070
Fax: (+44) 131 272 7001
Mail: Applications at the address on last page.
or contact your local Wolfson representative.
Additional information may be made available from time to time on our web site at:
http://www.wolfsonmicro.com
WM8761-EV1M
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WM8761-EV1M
IMPORTANT NOTICE
Wolfson Microelectronics plc (W M) 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 W M’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
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.
stated by WM for that
ADDRESS:
Wolfson Microelectronics plc
Westfield House
26 Westfield Road
Edinburgh
EH11 2QB
United Kingdom
Tel :: +44 (0)131 272 7000
Fax :: +44 (0)131 272 7001
Email :: apps@wolfsonmicro.com
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