19-3742; Rev 0; 9/05
MAX9706 Evaluation Kit
General Description
The MAX9706 evaluation kit (EV kit) is a fully assembled
and tested circuit board that evaluates the MAX9706
as well as the MAX9707 ICs. The MAX9706/MAX9707
contain three Class D amplifiers with an internal active
crossover to provide stereo highpass outputs and a
mono lowpass output. The IC does not require any
external components for the active crossover filter. The
MAX9706 also features a DirectDrive
TM
stereo head-
phone amplifier.
The MAX9706 speaker amplifier operates from a 4.5V
to 5.5V DC power supply, and delivers 2.3W continuous
power into each of three 4Ω speakers. Three different
speaker output filtering options are available for ease of
evaluation (see the
Output Filtering
section).
The MAX9706 headphone amplifier operates from a 3V
to 5.5V DC power supply, and delivers up to 95mW per
channel into a 16Ω stereo headphone. When the
MAX9706 headphone sense detects the insertion of a
headphone, the MAX9706 automatically enters the
headphone mode.
The EV kit offers an option to select between fixed-fre-
quency modulation (FFM) mode or spread-spectrum
modulation (SSM) mode. The EV kit can be synchro-
nized with an external clock, and the EV kit provides a
synchronization output that allows multiple units to be
cascaded in a system.
The MAX9706 EV kit gain is jumper selectable. The EV
kit also features an option to select the crossover fre-
quency between the stereo highpass outputs and the
mono lowpass output. The MAX9706 shutdown supply
current is only 0.5µA (typ).
Features
♦
4.5V to 5.5V Single DC Power-Supply Operation
♦
Drives 3 x 2.3W into Three 4Ω Speakers
(2.1 Speaker Solutions)
♦
Drives 2 x 95mW into a 16Ω Stereo Headphone
(MAX9706)
♦
Internal Active Crossover Filter with Selectable
Crossover Frequency
♦
Selectable Gains
♦
Selectable Between Spread-Spectrum and Fixed-
Frequency Modulation
♦
Input and Output Synchronization Signals
♦
0.5µA (typ) Shutdown Current
♦
Space-Saving 36-Pin TQFN (6mm x 6mm x 0.8mm)
Package
♦
Fully Assembled and Tested
♦
Evaluates MAX9707 (IC Replacement Required)
Evaluates: MAX9706/MAX9707
Ordering Information
PART
MAX9706EVKIT
TEMP RANGE
0°C to +70°C*
IC PACKAGE
36-TQFN-EP**
(6mm x 6mm x 0.8mm)
*This
limited temperature range is for the EV kit PC board only.
The MAX9706 IC temperature range is -40°C to +85°C.
**EP
= Exposed paddle.
Component List
DESIGNATION
C3, C5
QTY
2
DESCRIPTION
0.1µF ±10%, 10V X7R ceramic
capacitors (0402)
TDK C1005X7R1A104K
1µF ±10%, 10V X7R ceramic
capacitors (0603)
TDK C1608X7R1A105K
0.47µF ±10%, 10V X7R ceramic
capacitors (0603)
TDK C1608X7R1A474K
MAX9706ETX
(36-pin TQFN-EP, 6mm x 6mm)
DESIGNATION
QTY
DESCRIPTION
OPTIONAL COMPONENTS FOR CUSTOMER EVALUATION
C1, C36
2
1000pF ±10%, 50V X7R ceramic
capacitors (0603)
TDK C1608X7R1H102K
100µF ±20%, 6.3V X5R ceramic
capacitor (1210)
TDK C3225X5R0J107M
Not installed, capacitors (0603)
100pF ±10%, 50V C0G ceramic
capacitors (0603)
TDK C1608C0G1H101K
C4, C6, C7, C10,
C12, C13, C14
7
C2
†
1
0
2
C8, C9, C11
3
C15–C35
C37, C38
†
System-level
U1
1
requirement.
Component List continued on next page.
________________________________________________________________
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.
MAX9706 Evaluation Kit
Evaluates: MAX9706/MAX9707
Component List (continued)
DESIGNATION
J1
JU1–JU7
JU8
L1
QTY
1
7
1
1
DESCRIPTION
3.5mm switched stereo jack
3-pin headers
2-pin header
Ferrite bead, 30Ω at 100MHz,
10mΩ DCR, 5A (0805)
TDK MPZ2012S300A
Ferrite beads, 100Ω at 100MHz,
50mΩ DCR, 3A (0603)
TDK MPZ1608S101A
DESIGNATION
QTY
DESCRIPTION
Not installed, inductors
Sumida CDRH6D38 series
recommended
Not installed, resistors (0603)
Not installed,
common-mode chokes
50VDC, 1.5ADC, 600Ω at 100MHz
TDK ACM4532-601-2P-X
recommended
Shunts
MAX9706 EV kit PC board
OPTIONAL COMPONENTS FOR CUSTOMER EVALUATION
OPTIONAL COMPONENTS FOR CUSTOMER EVALUATION
L4–L9
R1–R6
0
0
T1, T2, T3
0
L2, L3, L10
3
—
—
8
1
Component Suppliers
SUPPLIER
Sumida USA
TDK
PHONE
847-545-6700
847-803-6100
FAX
847-545-6720
847-390-4405
WEBSITE
www.sumida.com
www.component.tdk.com
Note:
Indicate that you are using the MAX9706 EV kit when contacting these component suppliers.
Quick Start
Recommended Equipment
•
•
•
•
•
One 5V, 2A DC power supply
Optional 3V, 1A DC power supply
Audio source
Three 4Ω to 8Ω speakers
Stereo headphone
7) Connect the first speaker to the OUTL+ and the
OUTL- test points.
8) Connect the second speaker to the OUTR+ and the
OUTR- test points.
9) Connect the third speaker to the OUTM+ and the
OUTM- test points.
10) Connect the +5V DC power supply to the VDD pad.
Connect the power-supply ground to the GND pad.
Procedures
The MAX9706 EV kit is fully assembled and tested.
Follow the steps listed below to verify board operation.
Do not turn on the power supply until all connec-
tions are completed.
1) Install a shunt across pins 1 and 2 of jumper JU1
(EV kit ON).
2) Install a shunt across pins 1 and 2 of jumper JU2
(mono speaker gain offset = -7.5dB).
3) Install a shunt across pins 1 and 2 of jumpers JU3
and JU4 (stereo speaker gain = +13.5dB, mono
speaker gain = +12dB, headphone gain = +3dB).
4) Install a shunt across pins 1 and 2 of jumpers JU5
and JU6 (crossover frequency = 2133.3Hz).
5) Install a shunt across pins 1 and 2 of jumper JU7
(SSM mode with frequency = 1150kHz ±50kHz).
6) Install a shunt on jumper JU8 (speaker enable).
2
11) Connect the +3V DC power supply to the HPVDD
pad. Connect the power-supply ground to the GND
pad. If the optional +3V DC power supply is not
available, connect the HPVDD pad to the VDD pad.
12) Connect the audio source to the IN_L and the IN_R
pads. Connect the audio source ground to the
GND pad.
13) Turn on both power supplies and the audio source.
14) To test the headphone, plug the headphone to the
phone jack J1.
Detailed Description
The MAX9706 EV kit is designed to evaluate the
MAX9706 as well as the MAX9707 ICs. The MAX9706/
MAX9707 contain three Class D amplifiers with an inter-
nal active crossover to provide stereo highpass outputs
and a mono lowpass output. The MAX9706 also fea-
tures a DirectDrive stereo headphone amplifier. The EV
kit comes with the MAX9706 IC installed.
____________________________________________________________________________________________________
MAX9706 Evaluation Kit
The EV kit’s speaker amplifiers operate from a 4.5V to
5.5V DC power supply, and deliver 3 x 2.3W continu-
ous power into three 4Ω speakers. Three different
speaker output filtering options are available for ease of
evaluation. See the
Output Filtering
section.
The EV kit’s DirectDrive headphone amplifier operates
from a 3V to 5.5V DC power supply, and delivers 95mW
per channel into a 16Ω stereo headphone. Both the
speaker and headphone power supplies must be pre-
sent to operate the EV kit. The EV kit can be powered
by a single 4.5V to 5.5V DC power supply.
The EV kit offers an option to select between two frequen-
cies when in fixed-frequency modulation (FFM) mode or a
single-center frequency in spread-spectrum modulation
(SSM) mode. The MAX9706 EV kit features a synchro-
nization input (SYNCIN) PC board pad that allows the
MAX9706 to synchronize with an external clock. The EV
kit also provides a synchronization output (SYNCOUT) PC
board pad to synchronize other devices to the MAX9706.
Refer to the
Operating Modes
section in the MAX9706/
MAX9707 IC data sheet for additional information on FFM,
SSM, SYNCIN, and SYNCOUT.
The MAX9706’s speaker and headphone amplifier gain
is configurable using jumpers JU3 and JU4. The mono
output gain offset is configurable using jumper JU2.
The MAX9706 EV kit also provides a line-level mono-
output MONO_OUT PC board pad.
The MAX9706 EV kit features an option to select the
crossover frequency between the stereo highpass and
mono lowpass frequencies. The crossover frequency is
jumper selectable using jumpers JU5 and JU6. Refer to
the
Crossover Frequency
section in the MAX9706/
MAX9707 IC data sheet for additional information on
the internal active crossover.
The speaker and headphone outputs on the EV kit can be
selected by jumper JU8 and headphone jack J1. See
Table 8 in the
Jumper Selection
section.
The EV kit can also evaluate the MAX9707. To evaluate
the MAX9707, replace the MAX9706 with the MAX9707.
See the
Evaluating the MAX9707
section.
Evaluates: MAX9706/MAX9707
Output Filtering
The speaker outputs (OUTL+/-, OUTR+/-, and OUTM+/-)
can be connected directly to three speaker loads without
any filtering. Use the OUTL+/-, OUTR+/-, and OUTM+/-
test points to connect the left, right, and mono speakers
directly to the EV kit.
The MAX9706 EV kit features PC board pads for filters
that can be added to ease evaluation. Audio analyzers
typically cannot accept pulse-width-modulated (PWM)
signals at their inputs. The PWM output signal can be
lowpass-filtered by installing components: L4–L9,
C21–C35, and R1–R6 to use the filtering output pads
(FOUTL+/-, FOUTR+/-, and FOUTM+/-). See Table 1 for
the suggested filtering component values to evaluate a
4Ω load with a 30kHz cutoff frequency.
The MAX9706/MAX9707 are designed to pass FCC
Class B RF emissions without additional filtering. In
applications where a long cable is required, or the cir-
cuit is near EMI-sensitive devices, output capacitors
C15–C20, and common-mode chokes T1–T3, can be
added to reduce radiated emissions. Table 2 lists the
recommended EMI filter components. Refer to the
Applications Information, Filterless Class D Operation
section in the MAX9706/MAX9707 IC data sheet for
additional information.
Table 1. Suggested Filtering Components
for a 4Ω Load with a 30kHz Cutoff
Frequency
COMPONENT
C21–C26
DESCRIPTION
0.033µF ±10%, 25V X7R ceramic
capacitors (0603)
TDK C1608X7R1E333K
0.15µF ±10%, 25V X7R ceramic
capacitors (0603)
TDK C1608X7R1E154K
0.068µF ±10%, 25V X7R ceramic
capacitors (0603)
TDK C1608X7R1E683K
22µH ±20%, 1.3A inductors
Sumida CDRH6D38-220
22Ω ±5% resistors (0603)
Table 2. Recommended EMI Filter
Components
COMPONENT
C15–C20
DESCRIPTION
100pF ±10%, 50V C0G ceramic
capacitors (0603)
TDK C1608C0G1H101K
Common-mode chokes, 50VDC,
1.5ADC, 600Ω at 100MHz
TDK ACM4532-601-2P-X
C27, C28, C29
C30–C35
T1, T2, T3
L4–L9
R1–R6
_______________________________________________________________________________________
3
MAX9706 Evaluation Kit
Evaluates: MAX9706/MAX9707
Jumper Selection
Shutdown Mode (
SHDN
)
Jumper JU1 controls the shutdown mode (SHDN) of the
MAX9706/MAX9707 ICs. The shutdown mode can also
be controlled by an external logic controller connected
to the EV kit
SHDN
PC board pad. Remove the shunt
from jumper JU1 before connecting an external con-
troller to the
SHDN
PC board pad. See Table 3 for
shunt positions.
Mono Gain Offset Selection (MGAIN)
The MAX9706/MAX9707’s mono channel is the sum of
the left and right channels. Therefore, the mono chan-
nel has a +6dB gain higher than that of the left or the
right channels. The MAX9706/MAX9707 provides an
option to offset this +6dB gain. Jumper JU2 selects the
mono amplifier gain offset on the EV kit. See Table 4 for
shunt positions.
Gain Selection (GAIN1, GAIN2)
Jumpers JU3 and JU4 provide an option to set the
speaker and headphone amplifiers’ gain on the EV kit.
See Table 5 for shunt positions. Note that the stereo
speaker outputs are highpass-filtered by the crossover
circuitry. The mono speaker output is lowpass-filtered
by the crossover circuitry while the stereo headphone
output has full bandwidth.
Crossover Frequency Selection (FS0, FS1)
Jumpers JU5 and JU6 provide an option to set the
crossover frequency between stereo highpass outputs
and the mono lowpass output for the MAX9706 EV kit.
See Table 6 for shunt positions.
Synchronous Switching Input (SYNCIN)
The MAX9706 EV kit provides a SYNCIN PC board pad
that allows the MAX9706/MAX9707 switching frequency
to synchronize to an external TTL clock. The external
clock frequency can range from 1MHz to 1.5MHz and
can have any duty cycle, but the minimum pulse width
must be greater than 100ns. The SYNCIN input on the
EV kit also selects between the FFM and SSM mode for
the MAX9706. Jumper JU7 selects between the FFM
and SSM mode options for the MAX9706/MAX9707 ICs.
See Table 7 for shunt positions.
Table 3. JU1 Jumper Selection (SHDN)
SHUNT
POSITION
1-2
(Default)
2-3
None.
External logic
controller connected
to
SHDN
pad.
SHDN
PIN
High
Low
Connected to
external
controller.
EV KIT
FUNCTION
Enabled
Disabled
SHDN
driven by
external logic
controller. Shutdown
is active low.
Table 4. JU2 Jumper Selection (MGAIN
Offset)
SHUNT
POSITION
1-2*
Not Installed*
2-3*
MGAIN
PIN
High
Unconnected
Low
MONO AMPLIFIER
GAIN OFFSET
(dB)
-7.5
-6.0
-4.5
*JU8
installed. Headphone not plugged in.
Table 5. JU3 and JU4 Jumper Selection (GAIN)
SHUNT
POSITION
JU3
(GAIN2)
2-3 (Low)
2-3 (Low)
1-2 (High)
1-2 (High)
JU4
(GAIN1)
2-3 (Low)
1-2 (High)
2-3 (Low)
1-2 (High)
SPEAKER GAIN (dB)
JU8 INSTALLED
JU2 NOT INSTALLED
+9.0
+10.5
+12.0
+13.5
HEADPHONE GAIN (dB)
JU8 NOT INSTALLED
0
0
+3
+3
4
_______________________________________________________________________________________
MAX9706 Evaluation Kit
Evaluates: MAX9706/MAX9707
Speaker/Headphone Mode (HPS)
Jumper JU8 selects between the speaker mode and the
headphone mode for the MAX9706 EV kit. See Table 8
for shunt positions.
Evaluating the MAX9707
To evaluate the MAX9707, replace the MAX9706 IC with
the MAX9707 IC. Refer to the MAX9706/MAX9707 IC
data sheet for the pinout and function.
Table 6. JU5 and JU6 Jumper Selection
(Crossover Frequency)
SHUNT POSITION
JU5
(FS0)
2-3 (Low)
2-3 (Low)
1-2 (High)
1-2 (High)
JU6
(FS1)
2-3 (Low)
1-2 (High)
2-3 (Low)
1-2 (High)
CROSSOVER
FREQUENCY (Hz)
800
1066.7
1600
2133.3
Table 8. JU8 Jumper Selection (SPKR/HP)
SHUNT
POSITION
Not Installed
Installed
(No headphone plugged into J1)
Installed
(Headphone plugged into J1)
EV KIT
FUNCTION
Forced headphone
mode
Speaker mode
Headphone mode
Table 7. JU7 Jumper Selection (Switching
Frequency)
SHUNT
POSITION
SYNC_IN
CONNECTED
TO
OPERATING
MODE
SSM with
f
OSC
= 1150kHz
± 50kHz
FFM with
f
OSC
= 1340kHz
FFM with
f
OSC
= 1100kHz
FFM with
f
OSC
= external
clock frequency.
1-2
(Default)
Not Installed
2-3
Not Installed.
External clock source
connected to
SYNCIN pad.
VDD
Unconnected
GND
External clock
source from
1MHz to
1.5MHz.
_______________________________________________________________________________________
5
RF/无线
