19-0776; Rev 0; 3/07
MAX9776 Evaluation Kit
General Description
The MAX9776 evaluation kit (EV kit) is a fully assembled
and tested printed circuit board (PCB) that evaluates
the MAX9776 ultra-low EMI, 1.5W filterless Class D
audio power amplifier with 80mW DirectDrive™ head-
phone amplifier. The MAX9776 EV kit offers highly pro-
grammable and flexible input and output routing, which
allows many combinations of balanced and single-
ended signals to be connected. The MAX9776 EV kit
also includes Windows
®
98SE/2000/XP-compatible
software, which provides a simple graphical user inter-
face (GUI) for exercising the MAX9776’s features.
Windows is a registered trademark of Microsoft Corp.
Features
o
1.5W Speaker Output (4Ω, V
DD
= 5V)
o
80mW DirectDrive Headphone Amplifier
o
Highly Programmable Input and Output Modes
o
Controlled Through USB
o
Proven PCB Layout
o
Windows 98SE/2000/XP-Compatible Evaluation
Software
o
Fully Assembled and Tested
Evaluates: MAX9776
Component Suppliers
SUPPLIER
AVX
TDK
TOKO
PHONE
843-946-0238
847-803-6100
847-297-0070
WEBSITE
www.avxcorp.com
www.component.tdk.com
www.tokoam.com
PART
MAX9776EVKIT+
Ordering Information
TYPE
EV kit
INTERFACE
USB interface
+Denotes
a lead-free and RoHS-compliant EV kit.
Note:
Indicate that you are using the MAX9776 when contact-
ing these component suppliers.
Component List
DESIGNATION
C1–C6
QTY
6
DESCRIPTION
100pF ±5%, 10V C0G ceramic
capacitors (0603)
TDK C1608C0G1H101K
0.01µF ±10%, 25V X7R ceramic
capacitor (0603)
TDK C1608X7R1H103J
0.1µF ±10%, 25V X7R ceramic
capacitors (0603)
TDK C1608X7R1E104J
1.0µF ±10%, 16V X5R ceramic
capacitors (0603)
TDK C1608X5R1C105M
33µF ±10%, 10V tantalum
capacitors (C-case)
AVX TAJC336K010R
0.47µF ±10%, 10V X7R ceramic
capacitor (0603)
TDK C1608X7R1C474K
0.033µF ±10%, 10V X7R ceramic
capacitors (0603)
TDK C1608X7R1H333K
Not installed (0603)
3300pF ±10%, 10V X7R ceramic
capacitor (0603)
TDK C1608X7R1H332K
DESIGNATION
C51, C52, C53
QTY
3
DESCRIPTION
10µF ±10%, 16V X5R ceramic
capacitors (1206)
TDK C3216X5R1C106M
22pF ±5%, 10V C0G ceramic
capacitors (0603)
TDK C1608C0G1H220J
10pF ±5%, 10V C0G ceramic
capacitors (0603)
TDK C1608C0G1H100J
Green LED (0603)
Not installed (0603)
Red LED (0603)
0Ω resistors (0603)
0Ω resistors (1206)
Ferrite beads, 3A (1206)
3.5mm surface-mount stereo
headphone jack
USB series “B” right-angle PC
mount receptacle
Not installed
2-pin single-row headers
3-pin single-row header
33µH ±20%, 1.4A inductors
TOKO B1000AS-330M
C11
C12, C28, C29,
C41–C48, C58
C13–C23, C49,
C50
C24, C25
1
C54, C55
2
12
C56, C57
D1
D2
D3
FB1–FB6, FB13
FB7, FB8
FB11, FB12
HPJK
J1
J2
JU1–JU5
JU6
L1, L2
2
1
0
1
7
2
2
1
1
0
5
1
2
13
2
C26
1
C32, C33
C36, C37
C40
2
0
1
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MAX9776 Evaluation Kit
Evaluates: MAX9776
Component List (continued)
DESIGNATION
R1, R2, R18
R3, R4
R7–R10
R11
R12
R13, R14, R15
R16
R17
R19
U1
U2
U3
U4
U5
U6
Y1
Y2
Y3
—
—
—
QTY
0
2
4
1
1
3
1
1
1
1
1
1
1
1
1
1
1
0
6
1
1
DESCRIPTION
Not installed, resistors
22Ω ±5% resistors (0603)
27Ω ±5% resistors (0603)
220Ω ±5% resistor (0603)
470Ω ±5% resistor (0603)
1.5kΩ ±5% resistors (0603)
2.2kΩ ±5% resistor (0603)
10kΩ ±5% resistor (0603)
1kΩ ±5% resistor (0603)
MAX9776ETJ+ (32 TQFN, 5mm x
5mm x 0.8mm)
MAXQ2000-RAX+ (68-pin QFN-EP)
93C46 type 3-wire EEPROM
(8-pin SO)
FTDI FT232BL (TQFP-32L, 7mm x
7mm)
MAX8511EXK33+T (SC70-5)
MAX8511EXK25+T (SC70-5)
16MHz crystal
6MHz crystal
Not installed
Shunts
PCB: MAX9776 Evaluation Kit+
USB high-speed A-to-B cable
(1.5m)
Procedure
Do not turn on the power supply until all connections
are made:
1) Visit the Maxim Integrated Products website
(www.maxim-ic.com/evkitsoftware) to download the
latest version of the EV kit software, 9776Rxx.ZIP.
Save the EV kit software to a temporary folder and
unzip the 9776Rxx.ZIP file.
2) Install the MAX9776 evaluation software on your
computer by running the INSTALL.EXE program.
The program files are copied and icons are created
in the Windows
Start | Programs
menu.
3) Make sure the shunts of all jumpers on the MAX9776
EV kit are in the following default positions.
JU1: (Open)
JU2: (Open)
JU3: (Open)
JU4: (1-2)
INA is stereo input
INB is stereo input
INC is stereo input
4)
5)
6)
7)
8)
Quick Start
Recommended Equipment
• 5V, 1.5A power supply
Stereo audio source (i.e., CD player, MP3 player)
One 4Ω (or 8Ω) speaker
The MAX9776 EV kit (included with USB cable)
A user-supplied Windows 98SE/2000/XP PC with a
spare USB port
Note:
In the following section(s), software-related items
are identified by bolding. Text in
bold
refers to items
directly from the EV kit software. Text in
bold and
underlined
refers to items from the Windows
98SE/2000/XP operating system.
•
•
•
•
SDA connected to on-board micro-
controller
JU5: (1-2)
SCL connected to on-board micro-
controller
JU6: (1-2)
Normal operation
Connect the speaker across FOUT+ and FOUT-
pads.
Connect the positive terminal of the 5V power sup-
ply to the VDD pad and the ground terminal of the
power supply to the GND pad.
Connect the stereo audio source across the INA1,
INA2, and GND pads.
Turn on the audio sources, and then turn on the
power supply.
Connect the USB cable from the PC to the MAX9776
EV kit board. A
Building Driver Database
window
pops up in addition to a
New Hardware Found
mes-
sage if this is the first time the EV kit board is con-
nected to the PC. If you do not see a window that is
similar to the one described above after 30s, remove
the USB cable from the MAX9776 EV kit and recon-
nect it. Administrator privileges are required to install
the USB device driver on Windows 2000/XP. Refer to
the TROUBLESHOOTING_USB.PDF document
included with the software if you have any problems
during this step.
2
_______________________________________________________________________________________
MAX9776 Evaluation Kit
9) Follow the directions of the
Add New Hardware
Wizard
to install the USB device driver. Choose the
Search for the best driver for your device
option.
Specify the location of the device driver to be
C:\Program Files\MAX9776
(default installation
directory) using the
Browse
button.
10) Start the MAX9776 EV kit software by opening its
icon in the
Start
menu.
11) Check the
Power Up
checkbox in the
Control
Register
panel.
12) Ensure the audio signal is audible in the speaker.
The EV kit software automatically detects the
MAX9776 EV kit, enables the mono Class D speak-
er amplifier, and mixes the stereo input signal to a
mono signal. The mono signal is sent to the mono
Class D output.
Evaluates: MAX9776
Detailed Description of Software
The MAX9776 EV kit GUI software provides an easy
user interface (Figure 1) to control the programmable
features of the MAX9776. To start the MAX9776 EV kit
GUI software, double-click the MAX9776 EV kit icon
created during installation. The user will have to wait
approximately 2s while the software detects the
MAX9776 EV kit.
Figure 1. MAX9776 EV Kit Software GUI Window
_______________________________________________________________________________________
3
MAX9776 Evaluation Kit
Evaluates: MAX9776
Input Select and Status
The
Input Select and Status
panel gives the capability
to select the input mode between single-ended stereo,
right-channel differential, left-channel differential, and
mono differential for input channels INA, INB, and INC.
The
Input Select and Status
panel also displays the
current volume settings for INA, INB, and INC. INA can
be configured to accept a stereo single-ended signal or
a differential mono signal. Click the
STEREO S/E
radio
button to configure INA for a stereo single-ended signal.
Click the
MONO DIFF
radio button to configure INA for a
mono differential input signal.
INB and INC can be configured to accept a stereo sin-
gle-ended signal or a differential signal. Check the
L,
R,
or
M
radio buttons to configure the input to accept a
differential signal and route that signal to either the
right, left, or mono mixer. Refer to the functional dia-
gram in the MAX9776 IC data sheet for details.
The input mode is also selectable using the
Input Mode
pulldown menu inside the
Input/Output Mode
panel.
Refer to the MAX9776 IC data sheet for details.
Control Register
The
Control Register
panel contains checkboxes for
the remaining settings. These checkboxes control the
INA gain boost, receiver gain boost, power up, 6dB
input gain boost, mute control, and Class D oscillator
mode. Check the
INA 20dB Boost
checkbox to apply
an extra 20dB of gain to the INA path. Checking the
Mono 6dB Boost
checkbox applies 6dB of gain to the
mono channel. Check the
Power Up
checkbox to
enable the MAX9776 EV kit, clear the checkbox to shut
down the kit.
Input 6dB Boost
applies an additional
6dB of gain to all the input paths. Check
Mute
to mute
the MAX9776 outputs. Check
Spread Spectrum Mode
to enable the low-EMI spread-spectrum mode. Check
Speaker Mono Mix
to enable mono mixing for the
speaker amplifier. If this box is not checked, only the
left channel will play at speaker output.
Reset, Help, and Exit Buttons
There are three buttons at the bottom-right corner of the
MAX9776 EV kit software GUI window:
Reset, Help,
and
Exit.
Press the
Reset
button to reestablish the connection
between the PC and the EV kit, and return the
MAX9776 EV kit to its power-on-reset setting.
The
Help
button displays the current software version.
It also provides information on how to obtain the latest
MAX9776 EV kit software and data sheet.
Press the
Exit
button to quit the MAX9776 EV kit software.
Output Select and Status
The output mode of the speaker, headphone, and
receiver amplifiers can be controlled within the
Output
Control and Status
panel.
The output mode of the speaker, headphone, and
receiver amplifiers can also be selected using the
Output Mode
pulldown menu inside the
Input/Output
Mode
panel. Refer to the MAX9776 IC data sheet
for details.
Detailed Description of Hardware
The MAX9776 EV kit board provides a proven layout for
evaluating the MAX9776. The EV kit comes with
MAX9776ETJ+.
Input/Output Mode
The input and output modes are selectable using the
pulldown menus inside this panel. Refer to the
MAX9776 IC data sheet for details.
Input Mode Setting
The audio input terminals on the MAX9776 EV kit are
flexible and can be configured as mono single-ended
inputs, stereo single-ended inputs, or differential inputs.
Any of the inputs can be routed to left, right, or mono
input mixers. Jumpers JU1–JU3 can be used to ground
INA2, INB2, and INC2, respectively.
Volume Control
The scroll bars inside the
Volume Control
panel individu-
ally control the volume setting of the MAX9776’s left chan-
nel, right channel, and mono channel. If the
Lock L/R
channel
checkbox is checked, the volume of both left and
right channels will be equal and change simultaneously.
The current volume settings for INA, INB, and INC inside
the
Input Select and Status
panel will be updated auto-
matically as the volume control scroll bar is moved.
Outputs
The MAX9776 EV kit allows connection of stereo head-
phones, a mono receiver speaker, and a mono loud-
speaker. A 3.5mm headphone jack is provided to con-
nect stereo headphones. The mono receiver speaker
output is labeled OUTRX. Connect the receiver speaker
between OUTRX and one of the adjacent GND pads.
4
_______________________________________________________________________________________
MAX9776 Evaluation Kit
Connect the mono loudspeaker between the FOUT+
and FOUT- pads.
connected between the VDD and GND pads. All other
support devices are powered from the USB supply.
Evaluates: MAX9776
Class D and EMI Filtering
Two types of filters are available on the Class D output.
One filter is an LCR filter intended to be used to connect
the Class D output to an audio analyzer or oscilloscope.
The output of this filter is between FOUT+ and FOUT-.
The second filter is an EMI filter consisting of ferrite
beads and capacitors. The ferrite beads and capaci-
tors are included in the MAX9776 EV kit’s shipping box.
Install the EMI filter by removing the 0Ω resistors from
pads FB7 and FB8 and installing the ferrite beads. Also
install the included capacitors on pads C36 and C37.
Be sure to remove inductors L1 and L2 before EMI test-
ing is started. Connect the load across test points
OUT+ and OUT-.
Hardware Shutdown Control
Jumper JU6 controls the hardware shutdown function
of the MAX9776 EV kit. This will shut down the entire
MAX9776 and reset all the registers to their power-on
defaults. See Table 1 for shutdown shunt positions.
Table 1. Hardware Shutdown Selection
(JU6)
POSITION
1-2*
2-3
FUNCTION
Normal operation
Power-down mode
*Default
position.
MAX9776
I
2
C/SMBus
I
2
C
User-Supplied I
2
C Interface
To use the MAX9776 EV kit with a user-supplied I
2
C
interface, remove the shunts on jumper JU4 and JU5.
Connect SDA, SCL, and GND lines from the user-
supplied I
2
C interface to the corresponding pads on
the MAX9776 EV kit board. Depending on the configu-
ration of the user-supplied I
2
C interface, it may be nec-
essary to install I
2
C pullup resistors R1 and R2.
Address
The MAX9776 is an
slave device that can
only be written to. The slave address is fixed to
1001101x in binary.
Power Supply
The MAX9776 EV kit board is powered from both a user-
supplied +2.7V to +5.5V supply, and the +5V USB sup-
ply. U1 is powered by a user-provided DC power supply
_______________________________________________________________________________________
5
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