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.
Features
1.5W Speaker Output (4Ω, VDD = 5V)
80mW DirectDrive Headphone Amplifier
Highly Programmable Input and Output Modes
Controlled Through USB
Proven PCB Layout
Windows 98SE/2000/XP-Compatible Evaluation
Software
Fully Assembled and Tested
Evaluates: MAX9776
MAX9776 Evaluation Kit
________________________________________________________________
Maxim Integrated Products
1
19-0776; Rev 0; 3/07
Component List
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.
Ordering Information
PART TYPE INTERFACE
MAX9776EVKIT+ EV kit USB interface
DESIGNATION QTY DESCRIPTION
C1–C6 6
100pF ±5%, 10V C0G ceramic
capacitors (0603)
TDK C1608C0G1H101K
C11 1
0.01µF ±10%, 25V X7R ceramic
capacitor (0603)
TDK C1608X7R1H103J
C12, C28, C29,
C41–C48, C58 12
0.1µF ±10%, 25V X7R ceramic
capacitors (0603)
TDK C1608X7R1E104J
C13–C23, C49,
C50 13
1.0µF ±10%, 16V X5R ceramic
capacitors (0603)
TDK C1608X5R1C105M
C24, C25 2
33µF ±10%, 10V tantalum
capacitors (C-case)
AVX TAJC336K010R
C26 1
0.47µF ±10%, 10V X7R ceramic
capacitor (0603)
TDK C1608X7R1C474K
C32, C33 2
0.033µF ±10%, 10V X7R ceramic
capacitors (0603)
TDK C1608X7R1H333K
C36, C37 0 Not installed (0603)
C40 1
3300pF ±10%, 10V X7R ceramic
capacitor (0603)
TDK C1608X7R1H332K
DESIGNATION QTY DESCRIPTION
C51, C52, C53 3
10µF ±10%, 16V X5R ceramic
capacitors (1206)
TDK C3216X5R1C106M
C54, C55 2
22pF ±5%, 10V C0G ceramic
capacitors (0603)
TDK C1608C0G1H220J
C56, C57 2
10pF ±5%, 10V C0G ceramic
capacitors (0603)
TDK C1608C0G1H100J
D1 1 Green LED (0603)
D2 0 Not installed (0603)
D3 1 Red LED (0603)
FB1–FB6, FB13 7 0Ω resistors (0603)
FB7, FB8 2 0Ω resistors (1206)
FB11, FB12 2 Ferrite beads, 3A (1206)
HPJK 1 3.5mm surface-mount stereo
headphone jack
J1 1 USB series “B” right-angle PC
mount receptacle
J2 0 Not installed
JU1–JU5 5 2-pin single-row headers
JU6 1 3-pin single-row header
L1, L2 2 33µH ±20%, 1.4A inductors
TOKO B1000AS-330M
+
Denotes a lead-free and RoHS-compliant EV kit.
Windows is a registered trademark of Microsoft Corp.
Component Suppliers
SUPPLIER PHONE WEBSITE
AVX 843-946-0238 www.avxcorp.com
TDK 847-803-6100 www.component.tdk.com
TOKO 847-297-0070 www.tokoam.com
Note: Indicate that you are using the MAX9776 when contact-
ing these component suppliers.
Evaluates: MAX9776
MAX9776 Evaluation Kit
2 _______________________________________________________________________________________
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.
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) INA is stereo input
JU2: (Open) INB is stereo input
JU3: (Open) INC is stereo input
JU4: (1-2) SDA connected to on-board micro-
controller
JU5: (1-2) SCL connected to on-board micro-
controller
JU6: (1-2) Normal operation
4) Connect the speaker across FOUT+ and FOUT-
pads.
5) 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.
6) Connect the stereo audio source across the INA1,
INA2, and GND pads.
7) Turn on the audio sources, and then turn on the
power supply.
8) 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.
Component List (continued)
DESIGNATION QTY DESCRIPTION
R1, R2, R18 0 Not installed, resistors
R3, R4 2 22Ω ±5% resistors (0603)
R7–R10 4 27Ω ±5% resistors (0603)
R11 1 220Ω ±5% resistor (0603)
R12 1 470Ω ±5% resistor (0603)
R13, R14, R15 3 1.5kΩ ±5% resistors (0603)
R16 1 2.2kΩ ±5% resistor (0603)
R17 1 10kΩ ±5% resistor (0603)
R19 1 1kΩ ±5% resistor (0603)
U1 1 MAX9776ETJ+ (32 TQFN, 5mm x
5mm x 0.8mm)
U2 1 MAXQ2000-RAX+ (68-pin QFN-EP)
U3 1 93C46 type 3-wire EEPROM
(8-pin SO)
U4 1 FTDI FT232BL (TQFP-32L, 7mm x
7mm)
U5 1 MAX8511EXK33+T (SC70-5)
U6 1 MAX8511EXK25+T (SC70-5)
Y1 1 16MHz crystal
Y2 1 6MHz crystal
Y3 0 Not installed
— 6 Shunts
— 1 PCB: MAX9776 Evaluation Kit+
—1
USB high-speed A-to-B cable
(1.5m)
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.
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.
Evaluates: MAX9776
MAX9776 Evaluation Kit
_______________________________________________________________________________________ 3
Figure 1. MAX9776 EV Kit Software GUI Window
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 Mradio 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.
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.
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.
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.
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.
Detailed Description of Hardware
The MAX9776 EV kit board provides a proven layout for
evaluating the MAX9776. The EV kit comes with
MAX9776ETJ+.
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.
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.
MAX9776 Evaluation Kit
4 _______________________________________________________________________________________
Evaluates: MAX9776
MAX9776 Evaluation Kit
_______________________________________________________________________________________ 5
Connect the mono loudspeaker between the FOUT+
and FOUT- pads.
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 0Ωresistors 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-.
MAX9776 I
2
C Address
The MAX9776 is an I2C/SMBus 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
connected between the VDD and GND pads. All other
support devices are powered from the USB supply.
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.
User-Supplied I
2
C Interface
To use the MAX9776 EV kit with a user-supplied I2C
interface, remove the shunts on jumper JU4 and JU5.
Connect SDA, SCL, and GND lines from the user-
supplied I2C interface to the corresponding pads on
the MAX9776 EV kit board. Depending on the configu-
ration of the user-supplied I2C interface, it may be nec-
essary to install I2C pullup resistors R1 and R2.
Table 1. Hardware Shutdown Selection
(JU6)
POSITION FUNCTION
1-2* Normal operation
2-3 Power-down mode
*
Default position.
Evaluates: MAX9776
MAX9776 Evaluation Kit
6 _______________________________________________________________________________________
FGND
JU6
1
2
3
VDD
R2
OPEN
VDD
JU5
SCL
R1
OPEN
JU4
SDA
SDA
GND
SCL
JU3
INC2
GND
C6
100pF
C5
100pF
C4
100pF
C3
100pF
C2
100pF
C1
100pF
VDD
FB6
FB5
FB4
FB3
FB2
FB1
C17
1.0µF
C18
1.0µF
C16
1.0µF
C15
1.0µF
C13
1.0µF
C14
1.0µF
INA1
INA2
GND
INB1
JU1
INB2
GND
INC1
JU2
12
FGND
C23
1.0µF
C22
1.0µF
HPL
1
2
HPR
4
3HPJK
OUTRX
FGND
C37
OPEN
L2
33µH
OUT+
C36
OPEN
FGND
L1
33µH
OUT-
FB7
FB8
FGND
C58
0.1µF
C12
0.1µF
C24
33µF
10V
C21
1.0µF
C20
1.0µF
FB11
FB12
VDD
C19
1.0µF
C11
0.01µF
29
4
25
11
13
10
16
18
20
5
2
R3
22Ω
C28
0.1µF
C32
0.033µFFGND
FOUT-
FOUT+
C33
0.033µF
FGND
R4
22Ω
C29
0.1µF
C26
0.47µF
CPGND
PGND
PGND
GND
VBIAS
CIN
C1P
HPL
HPR
OUTRX
OUT+
OUT-
PVDD
CPVDD
VSS
CPVSS
VDD
INA1
INA2
INB1
INB2
INC1
INC2
SHDN
SCL
SDA
7823 26 28 31
N.C. N.C. N.C. N.C. N.C. N.C.
32
3
6
19
30
21 15 17 9 1
27
24
22
14
GND
VDD
GND
VDD
C25
33µF
10V
+
MAX9776
U1
FGND
Figure 2a. MAX9776 EV Kit Schematic (Sheet 1 of 3)
Evaluates: MAX9776
MAX9776 Evaluation Kit
_______________________________________________________________________________________ 7
+3.3V
2
D1
1
R11
220Ω
10
15
14
11 TRX
12
16
18
19
20
21
22
23
24
25 P71
P70
P52
P65
P53
P64
C48
0.1µF
+3.3V
13
+5V
26
+5V
3
R12
470Ω
+5V
C45
0.1µF
30
6
C40
3300pF
8
C43
0.1µF
+5V
C42
0.1µF
C53
10µF
FB13
C41
0.1µF
R9
27Ω
R10
27Ω
J1-1
J1-2
J1-3
J1-4
J1
USB
7
R13
1.5kΩ
5
+5V
4
C54
22pF
27
Y2
6MHz
C55
22pF
SLEEP
PWREN
PWRCTL
GNDGND
AGND
17
9
29
TEST
EEDATA
EESK
EECS
XTOUT
XTIN
RESET
RSTOUT
USBDP
USBDM
3V3OUT
AVCC VCC VCC VCCIO
RXLED
TXLED
TXDEN
RI
DCD
DSR
DTR
CTS
RTS
RXD
TXD
31
2
1
32
28
+5V
R16
2.2kΩ
R17
10kΩ
1
2
3
4
U3
93C46
CS
SK
DI
D0
8
6
7
5
VCC
ORG
N.C.
GND
C44
0.1µF
U4
FT232BL
SDA
SCL
+3.3V P61
P60
R14
1.5kΩ
R15
1.5kΩ
R7
27Ω
R8
27Ω
C51
10µF
+2.5V
5
2
OUT
GND
IN
SHDN
MAX8511
U6
OUT
GND
MAX8511
U5
IN
SHDN
C49
1.0µF
1
3
+5V
+5V
+5V
5
2
+3.3V
C52
10µF
1
3
C50
1.0µF
Figure 2b. MAX9776 EV Kit Schematic (Sheet 2 of 3)
Evaluates: MAX9776
MAX9776 Evaluation Kit
8 _______________________________________________________________________________________
J2
JTAG +3.3V
J2-6
J2-3
J2-5
J2-9
J2-1
J2-4
J2-2
J2-10
J2-8
49
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
28
42
+2.5V
C46
0.1µF
18 19 20 21 22 23 24 25 26 29 30 31 32 33
35
34
36
37
38
39
Y3
OPEN
P53
P52
40
41
43
44
45
46
47
P61
P60
P65
P64
48
C57
10pF
C56
10pF
50
Y1
16MHz
+3.3V C47
0.1µF
27
51
68 67 66 65 64 63 61 60 59
62 58 57 56 55 54 53 52
P70P71
SEG28/P3.4/INT4
SEG29/P3.5/INT5
SEG30/P3.6/INT6
SEG31/P3.7/INT7
SEG32
SEG33/COM3
SEG34/COM2
SEG35/COM1
COM0
P4.0/TCK/INT18
P4.1/TDI/INT19
P4.2/TM5
P4.3/TD0
RESET
32KOUT
32KIN
P5.2/RX1/INT10
P5.3/TX1/INT11
P5.4/SS
P5.5/MOSI
P5.6/SCLK
P5.7/MISO
P6.0/T18/INT12
P6.1/T1/INT13
P6.2/T2B/OW_OUT
P6.3/T2/OW_IN
P6.4/TOB/WKOUT0
P6.5/TO/WKOUT1
HFXOUT
HFXIN
VDDI0
GND
GND
SEG27/P3.3
SEG26/P3.2
SEG25/P3.1
SEG23/P2.7
SEG22/P2.6
SEG21/P2.5
SEG20/P2.4
SEG19/P2.3
SEG18/P2.2
SEG17/P2.1
SEG16/P2.0
SEG15/P1.7
SEG14/P1.6
SEG13/P1.5
SEG12/P1.4
SEG11/P1.3
SEG24/P3.0
VDD
SEG10/P1.2
SEG9/P1.1
SEG8/P1.0
SEG7/P0.7/INT3
SEG6/P0.6/INT2
SEG5/P0.5/INT1
SEG4/P0.4/INT0
SEG3/P0.3
SEG2/P0.2
SEG1/P0.1
SEG0/P0.0
VADJ
VLCD2
VLCD1
VLCD
P7.1/RX0/INT15
P7.0/TX0/INT14
+3.3V
21
D2
1
2
D3
R18
OPEN
R19
1kΩ
TRX
MAXQ2000
U2
Figure 2b. MAX9776 EV Kit Schematic (Sheet 3 of 3) (continued)
Evaluates: MAX9776
MAX9776 Evaluation Kit
_______________________________________________________________________________________ 9
Figure 3. MAX9776 EV Kit Component Placement Guide—
Component Side
Figure 4. MAX9776 EV Kit PCB Layout—Component Side
Evaluates: MAX9776
MAX9776 Evaluation Kit
10 ______________________________________________________________________________________
Figure 5. MAX9776 EV Kit PCB Layout—Layer 2 (GND) Figure 6. MAX9776 EV Kit PCB Layout—Layer 3 (Power)
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________
11
© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
Evaluates: MAX9776
MAX9776 Evaluation Kit
Boblet
Figure 7. MAX9776 EV Kit PCB Layout—Solder Side
