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For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX98400B Evaluation Kit
Evaluates: MAX98400B
General Description
The MAX98400B evaluation kit (EV kit) configures the
MAX98400B Class D amplifier to drive 2x12W into a pair
of 8I speakers in stereo mode for audio applications.
The EV kit operates from an 8V to 28V DC power supply.
The EV kit has a programmable gain and the jumper set-
tings default to a +20.1dB gain. The EV kit accepts a pair
of single-ended or differential input signals and provides
two sets of differential outputs for speakers.
The EV kit has two independent amplifier circuits, dem-
onstrating direct speaker driving (for low component
count) and filtered output driving (for ease of evaluation).
The EV kit comes with two MAX98400BETG+ devices
installed.
The EV kit provides an option to control the limiter,
thermal foldback, input configuration, gain, and shut-
down mode of the device. The EV kit includes convenient
audio input and output connectors.
Features
S 8V to 28V Single DC Power-Supply Operation
S Fully Differential Inputs and Outputs
S Drives 2x12W into 8I Speakers in Stereo Mode
S Limiter Control
S Thermal Foldback
S Shutdown Control
S Evaluates the MAX98400B in a 24-Pin TQFN
Package with an Exposed Pad
S U1 Configured for Filterless Output
S U2 Configured for Filtered Output
S Fully Assembled and Tested
Ordering Information
Component List
19-5505; Rev 0; 9/10
+Denotes lead(Pb)-free and RoHS compliant.
PART TYPE
MAX98400BEVKIT+ EV Kit
DESIGNATION QTY DESCRIPTION
FILTERLESS EVALUATION (U1)
C101 1
220FF Q20%, 35V electrolytic
capacitor (radial leaded,
5mm spacing), 10mm
diameter x 12.5mm high
Panasonic EEU-FM1V221
C102A, C102B 2
1FF Q10%, 50V X7R ceramic
capacitors (0805)
TDK C2012X7R1H105K
C103, C104 2
1FF Q10%, 10V X7R ceramic
capacitors (0603)
Murata GRM188R71A105K
C105–C108 4
1FF Q10%, 25V X7R ceramic
capacitors (0805)
Murata GRM21BR71E105K
C111–C114 0 Not installed, ceramic
capacitors (0603)
FB1 1
22I at 100MHz ferrite bead
(0805)
Murata BLM21PG220SN1D
DESIGNATION QTY DESCRIPTION
GAIN1_1, GAIN2_1,
LIM_1 3 3-pin headers
INL1 1 White phono jack
INR1 1 Red phono jack
JU104, JU105,
SHDN_1, TEMP_1 4 2-pin headers
L1+, L1-, R1+, R1- 0 Not installed, multipurpose
test points
R101, R103, R104,
R105 0 Not installed, resistors (0603)
R106 0 Not installed, potentiometer
(3/8in)
R107 1 100kI Q5% resistor (0603)
R111–R114 4 0I Q5% resistors (0805)
SPKL1+, SPKL1-,
SPKR1+, SPRK1- 4 Binding posts
U1 1
Stereo Class D audio
amplifier (24 TQFN-EP*)
Maxim MAX98400BETG+
MAX98400B Evaluation Kit
Evaluates: MAX98400B
2 ______________________________________________________________________________________
Component Suppliers
Note: Indicate that you are using the MAX98400B when contacting these component suppliers.
Component List (continued)
*EP = Exposed pad.
SUPPLIER PHONE WEBSITE
Central Semiconductor Corp. 631-435-1110 www.centralsemi.com
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
Panasonic Corp. 800-344-2112 www.panasonic.com
Sumida Corp. 847-545-6700 www.sumida.com
TDK Corp. 847-803-6100 www.component.tdk.com
Würth Electronik GmbH & Co. KG 201-785-8800 www.we-online.com
DESIGNATION QTY DESCRIPTION
— 10
600I at 100MHz, 150mI
DCR, 2A ferrite beads (0805)
Würth Elektronik 742792040
— 10
330pF Q10%, 50V X7R
ceramic capacitors (0603)
TDK C1608X7R1H331K
FILTERED EVALUATION (U2)
C201 1
220FF Q20%, 35V electrolytic
capacitor (radial leaded,
5mm spacing), 10mm
diameter x 12.5mm high
Panasonic EEU-FM1V221
C202A, C202B 2
1FF Q10%, 50V X7R ceramic
capacitors (0805)
TDK C2012X7R1H105K
C203, C204 2
1FF Q10%, 10V X7R ceramic
capacitors (0603)
Murata GRM188R71A105K
C205–C208 4
1FF Q10%, 25V X7R ceramic
capacitors (0805)
Murata GRM21BR71E105K
C220–C223,
C226–C229 8
0.15FF Q10%, 50V X7R
ceramic capacitors (0805)
Murata GRM21BR71H154K
C224, C225 2
0.68FF Q10%, 50V X7R
ceramic capacitors (0805)
Murata GRM21BR71H684K
FB2 1 22I ferrite bead (0805)
Murata BLM21PG220SN1D
FOUTL2+, FOUTL2-,
FOUTR2+, FOUTR2- 4 Binding posts
GAIN1_2, GAIN2_2,
LIM_2 3 3-pin headers
DESIGNATION QTY DESCRIPTION
INL2 1 White phono jack
INR2 1 Red phono jack
JU204, JU205 2 2-pin headers
L20–L23 4 33FH Q20%, 3.1A inductors
Sumida CDRH127NP-330NC
R201, R203,
R204, R205 0 Not installed, resistors (0603)
R206 0 Not installed, potentiometer
(3/8in)
R207 1 100kI Q5% resistor (0603)
R226–R229 4 15I Q5% resistors (1206)
U2 1
Stereo Class D audio
amplifier (24 TQFN-EP*)
Maxim MAX98400BETG+
COMMON TO BOTH SIDES
C1 1
0.1FF Q10%, 50V X7R
ceramic capacitor (0603)
Murata GRM188R71H104K
C2 1
1FF Q10%, 10V X7R ceramic
capacitor (0603)
Murata GRM188R71A105K
D1 1
4.3V, 20mA zener diode
(SOT23)
Central Semi CMPZ5229B
JU1 1 3-pin header
PGND, PVDD 2 Binding posts
R1 1 10kI Q5% resistor (0603)
— 13 Shunts
— 1 PCB: MAX98400B
EVALUATION KIT+
MAX98400B Evaluation Kit
Evaluates: MAX98400B
_______________________________________________________________________________________ 3
Quick Start
Required Equipment
• MAX98400BEVkit
• 8Vto28V,3ADCpowersupply
• Audiosourcewithvolumecontrol(e.g.,CDplayer)
• Twospeakers
Procedure—Filterless Evaluation (U1)
The EV kit is fully assembled and tested. Follow the
steps below to verify board operation. Caution: Do not
turn on the power supply until all connections are
completed.
1) Verify that all jumpers are in their default positions,
as shown in Table 1.
2) If not using the filtered evaluation side, remove the
shunt from SHDN_2 (disable).
3) Connect the first speaker across the SPKL1- and
SPKL1+ PCB binding posts.
4) Connect the second speaker across the SPKR1-
and SPKR1+ PCB binding posts.
5) Connect the positive terminal of the power supply
to the PVDD binding post and the power-supply
ground terminal to the PGND binding post.
6) Connect the left output terminal of the audio source
to the INL1 RCA phono jack.
7) Connect the right output terminal of the audio source
to the INR1 RCA phono jack.
8) Turn on the audio source at minimum volume.
9) Turn on the power supply.
10) Gradually increase the audio source volume until
audio is heard through the loud speakers.
Procedure—Filtered Evaluation (U2)
The EV kit is fully assembled and tested. Follow the
steps below to verify board operation. Caution: Do not
turn on the power supply until all connections are
completed.
1) Verify that all jumpers are in their default positions, as
shown in Table 2.
2) If not using the filterless evaluation side, remove the
shunt from SHDN_1 (disable).
3) Connect the first speaker across the FOUTL2- and
FOUTL2+ PCB binding posts.
4) Connect the second speaker across the FOUTR2-
and FOUTR2+ PCB binding posts.
5) Connect the positive terminal of the power supply
to the PVDD binding post and the power-supply
ground terminal to the PGND binding post.
6) Connect the left output terminal of the audio source
to the INL2 RCA phono jack.
7) Connect the right output terminal of the audio source
to the INR2 RCA phono jack.
8) Turn on the audio source at minimum volume.
9) Turn on the power supply.
10) Gradually increase the audio source volume until
audio is heard through the loud speakers.
Detailed Description of Hardware
The MAX98400B EV kit provides a proven layout for
evaluating the MAX98400B. The EV kit is designed to
evaluate the device in a 24-pin TQFN package with an
exposed pad. The device is a Class D amplifier that can
be configured to drive 2x12W into a pair of 8I speak-
ers. The EV kit operates from a DC power supply that
provides 8V to 28V and 3A of current. The EV kit PCB is
designed with two layers and has 2oz copper for opti-
mized power dissipation. Each side of the EV kit accepts
a pair of differential or single-ended input signals and
provides two sets of amplified differential audio outputs.
Optional External Preamplifier
Power Supply (VS)
The EV kit provides input pads (VS1 for U1 and VS2 for
U2) to accept an optional 5V external power supply for
powering the device’s preamplifiers. The external power
supply for the preamplifiers must be in the 4.5V to 5.5V
range. Refer to the MAX98400A/MAX98400B IC data
sheet for more information.
MAX98400B Evaluation Kit
Evaluates: MAX98400B
4 ______________________________________________________________________________________
Table 1. Jumper Descriptions (U1)
*Default position.
Filterless Output (U1)
The EV kit’s filterless outputs (SPKL1+/SPKL1- and
SPKR1+/SPKR1-) can be connected directly to a pair of
speaker loads without any filtering.
Output Filtering Requirements (U1)
The device can pass CE EN55022B regulations with only
ferrite-bead filters, especially when speaker-wire lengths
are less than or equal to 1m. To install the ferrite-bead
filters, first remove the 0I resistors (R111–R114). Next,
replace resistors R111–R114 with ferrite beads listed
in Table 3 (provided with the EV kit), and install filter
capacitors on the C111–C114 pads. The speaker wire
should be connected to the L1+/L1- and R1+/R1- test
points. Although component selection for the output filter
is dependent on speaker-wire length, the components in
Table 3 are provided with the EV kit as a starting point.
Final component selection should be determined during
EMC testing. Contact the factory, if required. Note that
an inductive load is required at this terminal. If using an
8I power resistor, add a 68FH series inductor. If using a
4I power resistor, add a 33FH series inductor.
Filtered Output (U2)
Audio analyzers typically cannot accept pulse-width
modulated (PWM) signals at their inputs. Therefore,
the EV kit features a pair of lowpass filters at each of
the outputs to ease evaluation. Use the filtering output
posts (FOUTL2+/FOUTL2- and FOUTR2+/FOUTR2-) to
connect the filtered PWM outputs to the audio analyzer.
The default lowpass filters at the EV kit outputs are opti-
mized for a pair of 8I power resistors or 8I speakers.
Thermal Foldback
As shipped from the factory, the thermal-foldback
feature is enabled (TEMP_1 and TEMP_2 jumpers open).
To disable thermal foldback, install a shunt across the
TEMP_1 or TEMP_2 jumper. Refer to the MAX98400A/
MAX98400B IC data sheet for information on selecting
this resistor value.
Limiter
As shipped from the factory, the limiter-threshold control
is disabled. To enable the limiter in PVDD tracking mode,
move the LIM_1 or LIM_2 shunt to the 2-3 position. To
enable the limiter in programmable mode, leave the
LIM_1 or LIM_2 jumper open and select appropriate val-
ues for R103, R104, and R105 or R203, R204, and R205.
Refer to the MAX98400A/MAX98400B IC data sheet for
information on selecting these component values.
JUMPER SHUNT
POSITION DESCRIPTION
SHDN_1 1-2* Normal operation; U1 SHDN =
DVDD (external logic-high)
Open Shutdown; U1 SHDN = GND
TEMP_1
Open* Thermal foldback enabled; U1
TEMPLOCK = unconnected
1-2 Thermal foldback disabled; U1
TEMPLOCK = GND
LIM_1
1-2* Limiter disabled; U1 LIM_TH =
VS1
2-3 Limiter enabled in PVDD tracking
mode; U1 LIM_TH = GND
Open
Limiter programmable mode; U1
LIM_TH is determined by R103,
R104, and R105
JUMPER SHUNT
POSITION DESCRIPTION
JU104
1-2* Single-ended input mode; U1
INL- = GND
Open Differential input mode; U1 INL-
is not connected to GND
JU105
1-2* Single-ended input mode; U1
INR- = GND
Open Differential input mode; U1 INR-
is not connected to GND
GAIN1_1
1-2 U1 G1 = VS1
2-3* U1 G1 = GND
Open U1 G1 is not driven
GAIN2_1
1-2 U1 G2 = VS1
2-3 U1 G2 = GND
Open* U1 G2 is not driven
MAX98400B Evaluation Kit
Evaluates: MAX98400B
_______________________________________________________________________________________ 5
Table 2. Jumper Descriptions (U2) Table 3. Recommended EMI Filter
Components for 8I Loads
*Default position.
Note: 3A current-rating ferrite beads are recommended for 4
I
load drive.
*GAIN1_1 and GAIN2_1 set the gain for U1.
GAIN1_2 and GAIN2_2 set the gain for U2.
Table 4. Gain Jumper Descriptions*
JUMPER SHUNT
POSITION DESCRIPTION
SHDN_2 1-2* Normal operation; U2 SHDN =
DVDD (external logic high)
Open Shutdown; U2 SHDN = GND
TEMP_2
Open* Thermal foldback enabled; U2
TEMPLOCK = unconnected
1-2 Thermal foldback disabled; U2
TEMPLOCK = GND
LIM_2
1-2* Limiter disabled; U2 LIM_TH =
VS2
2-3 Limiter enabled in PVDD tracking
mode; U2 LIM_TH = GND
Open
Limiter programmable mode; U2
LIM_TH is determined
by R203, R204, and R205
JU204
1-2* Single-ended input mode; U2
INL- = GND
Open Differential input mode; U2 INL-
is not connected to GND
JU205
1-2* Single-ended input mode; U2
INR- = GND
Open Differential input mode; U2 INR-
is not connected to GND
GAIN1_2
1-2 U2 G1 = VS2
2-3* U2 G1 = GND
Open U2 G1 is not driven
GAIN2_2
1-2 U2 G2 = VS2
2-3 U2 G2 = GND
Open* U2 G2 is not driven
DESIGNATION DESCRIPTION
R111–R114
600I at 100MHz, 150mI DCR,
2A ferrite beads (0805)
Würth Elektronik 742792040
C111–C114
330pF Q10%, 50V X7R
ceramic capacitors (0603)
Murata GRM188R71H331K or
TDK C1608X7R1H331K
SHUNT POSITION GAIN (dB)
GAIN1_1, GAIN1_2 GAIN2_1, GAIN2_2
2-3
2-3
9.0
Open 13.0
1-2 16.7
2-3
Open
20.1
Open 23.3
1-2 26.4
2-3
1-2
29.8
Open 32.9
1-2 Reserved
MAX98400B Evaluation Kit
Evaluates: MAX98400B
6 ______________________________________________________________________________________
Figure 1a. MAX98400B EV Kit Schematic (Sheet 1 of 3)
MAX98400B Evaluation Kit
Evaluates: MAX98400B
_______________________________________________________________________________________ 7
Figure 1b. MAX98400B EV Kit Schematic (Sheet 2 of 3)
MAX98400B Evaluation Kit
Evaluates: MAX98400B
8 ______________________________________________________________________________________
Figure 1c. MAX98400B EV Kit Schematic (Sheet 3 of 3)
MAX98400B Evaluation Kit
Evaluates: MAX98400B
_______________________________________________________________________________________ 9
Figure 2. MAX98400B EV Kit Component Placement Guide—Component Side
MAX98400B Evaluation Kit
Evaluates: MAX98400B
10 _____________________________________________________________________________________
Figure 3. MAX98400B EV Kit PCB Layout—Component Side
MAX98400B Evaluation Kit
Evaluates: MAX98400B
______________________________________________________________________________________ 11
Figure 4. MAX98400B EV Kit PCB Layout—Solder Side
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.
12 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX98400B Evaluation Kit
Evaluates: MAX98400B
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 9/10 Initial release —
