19-5505; Rev 0; 9/10
MAX98400B Evaluation Kit
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
Evaluates: MAX98400B
Package with an Exposed Pad
S
U1 Configured for Filterless Output
S
U2 Configured for Filtered Output
S
Fully Assembled and Tested
Ordering Information
PART
MAX98400BEVKIT+
TYPE
EV Kit
+Denotes
lead(Pb)-free and RoHS compliant.
Component List
DESIGNATION
QTY
DESCRIPTION
220FF
Q20%,
35V electrolytic
capacitor (radial leaded,
5mm spacing), 10mm
diameter x 12.5mm high
Panasonic EEU-FM1V221
1FF
Q10%,
50V X7R ceramic
capacitors (0805)
TDK C2012X7R1H105K
1FF
Q10%,
10V X7R ceramic
capacitors (0603)
Murata GRM188R71A105K
1FF
Q10%,
25V X7R ceramic
capacitors (0805)
Murata GRM21BR71E105K
Not installed, ceramic
capacitors (0603)
22I at 100MHz ferrite bead
(0805)
Murata BLM21PG220SN1D
DESIGNATION
GAIN1_1, GAIN2_1,
LIM_1
INL1
INR1
JU104, JU105,
SHDN_1,
TEMP_1
L1+, L1-, R1+, R1-
R101, R103, R104,
R105
R106
R107
R111–R114
SPKL1+, SPKL1-,
SPKR1+, SPRK1-
U1
QTY
3
1
1
4
0
0
0
1
4
4
1
DESCRIPTION
3-pin headers
White phono jack
Red phono jack
2-pin headers
Not installed, multipurpose
test points
Not installed, resistors (0603)
Not installed, potentiometer
(3/8in)
100kI
Q5%
resistor (0603)
0I
Q5%
resistors (0805)
Binding posts
Stereo Class D audio
amplifier (24 TQFN-EP*)
Maxim MAX98400BETG+
FILTERLESS EVALUATION (U1)
C101
1
C102A, C102B
2
C103, C104
2
C105–C108
C111–C114
4
0
FB1
1
_______________________________________________________________
Maxim Integrated Products
1
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
Component List (continued)
DESIGNATION
—
QTY
10
DESCRIPTION
600I at 100MHz, 150mI
DCR, 2A ferrite beads (0805)
Würth Elektronik 742792040
330pF
Q10%,
50V X7R
ceramic capacitors (0603)
TDK C1608X7R1H331K
220FF
Q20%,
35V electrolytic
capacitor (radial leaded,
5mm spacing), 10mm
diameter x 12.5mm high
Panasonic EEU-FM1V221
1FF
Q10%,
50V X7R ceramic
capacitors (0805)
TDK C2012X7R1H105K
1FF
Q10%,
10V X7R ceramic
capacitors (0603)
Murata GRM188R71A105K
1FF
Q10%,
25V X7R ceramic
capacitors (0805)
Murata GRM21BR71E105K
0.15FF
Q10%,
50V X7R
ceramic capacitors (0805)
Murata GRM21BR71H154K
0.68FF
Q10%,
50V X7R
ceramic capacitors (0805)
Murata GRM21BR71H684K
22I ferrite bead (0805)
Murata BLM21PG220SN1D
Binding posts
3-pin headers
DESIGNATION
INL2
INR2
JU204, JU205
L20–L23
R201, R203,
R204, R205
R206
R207
R226–R229
U2
QTY
1
1
2
4
0
0
1
4
1
DESCRIPTION
White phono jack
Red phono jack
2-pin headers
33FH
Q20%,
3.1A inductors
Sumida CDRH127NP-330NC
Not installed, resistors (0603)
Not installed, potentiometer
(3/8in)
100kI
Q5%
resistor (0603)
15I
Q5%
resistors (1206)
Stereo Class D audio
amplifier (24 TQFN-EP*)
Maxim MAX98400BETG+
0.1FF
Q10%,
50V X7R
ceramic capacitor (0603)
Murata GRM188R71H104K
1FF
Q10%,
10V X7R ceramic
capacitor (0603)
Murata GRM188R71A105K
4.3V, 20mA zener diode
(SOT23)
Central Semi CMPZ5229B
3-pin header
Binding posts
10kI
Q5%
resistor (0603)
Shunts
PCB: MAX98400B
EVALUATION KIT+
—
10
FILTERED EVALUATION (U2)
C201
1
C202A, C202B
2
COMMON TO BOTH SIDES
C1
1
C203, C204
2
C205–C208
C220–C223,
C226–C229
C224, C225
FB2
FOUTL2+, FOUTL2-,
FOUTR2+, FOUTR2-
GAIN1_2, GAIN2_2,
LIM_2
4
C2
1
8
D1
JU1
PGND, PVDD
R1
—
—
*EP
= Exposed pad.
1
1
2
1
13
1
2
1
4
3
Component Suppliers
SUPPLIER
Central Semiconductor Corp.
Murata Electronics North America, Inc.
Panasonic Corp.
Sumida Corp.
TDK Corp.
PHONE
631-435-1110
770-436-1300
800-344-2112
847-545-6700
847-803-6100
WEBSITE
www.centralsemi.com
www.murata-northamerica.com
www.panasonic.com
www.sumida.com
www.component.tdk.com
Würth Electronik GmbH & Co. KG
201-785-8800
www.we-online.com
Note:
Indicate that you are using the MAX98400B when contacting these component suppliers.
2
______________________________________________________________________________________
MAX98400B Evaluation Kit
Evaluates: MAX98400B
Quick Start
• MAX98400B EV kit
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).
Required Equipment
• 8V to 28V, 3A DC power supply
• Audio source with volume control (e.g., CD player)
• Two speakers
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)
2)
3)
4)
5)
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.
Procedure—Filterless Evaluation (U1)
Verify that all jumpers are in their default positions,
as shown in Table 1.
If not using the filtered evaluation side, remove the
shunt from
SHDN_2
(disable).
Connect the first speaker across the SPKL1- and
SPKL1+ PCB binding posts.
Connect the second speaker across the SPKR1-
and SPKR1+ PCB binding posts.
Connect the positive terminal of the power supply
to the PVDD binding post and the power-supply
ground terminal to the PGND binding post.
Connect the left output terminal of the audio source
to the INL1 RCA phono jack.
Connect the right output terminal of the audio source
to the INR1 RCA phono jack.
Turn on the audio source at minimum volume.
Turn on the power supply.
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.
6)
7)
8)
9)
10) Gradually increase the audio source volume until
audio is heard through the loud speakers.
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.
Procedure—Filtered Evaluation (U2)
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.
Optional External Preamplifier
Power Supply (VS)
_______________________________________________________________________________________
3
MAX98400B Evaluation Kit
Evaluates: MAX98400B
The EV kit’s filterless outputs (SPKL1+/SPKL1- and
SPKR1+/SPKR1-) can be connected directly to a pair of
speaker loads without any filtering.
Filterless Output (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.
Output Filtering Requirements (U1)
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.
Filtered Output (U2)
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.
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.
Thermal Foldback
Limiter
Table 1. Jumper Descriptions (U1)
JUMPER
SHUNT
POSITION
1-2*
Open
Open*
TEMP_1
1-2
1-2*
2-3
DESCRIPTION
Normal operation; U1
SHDN
=
DVDD (external logic-high)
Shutdown; U1
SHDN
= GND
Thermal foldback enabled; U1
TEMPLOCK = unconnected
Thermal foldback disabled; U1
TEMPLOCK = GND
Limiter disabled; U1 LIM_TH =
VS1
Limiter enabled in PVDD tracking
mode; U1 LIM_TH = GND
Limiter programmable mode; U1
LIM_TH is determined by R103,
R104, and R105
GAIN1_1
JU105
Open
1-2
2-3*
Open
1-2
GAIN2_1
2-3
Open*
JUMPER
SHUNT
POSITION
1-2*
JU104
Open
1-2*
DESCRIPTION
Single-ended input mode; U1
INL- = GND
Differential input mode; U1 INL-
is not connected to GND
Single-ended input mode; U1
INR- = GND
Differential input mode; U1 INR-
is not connected to GND
U1 G1 = VS1
U1 G1 = GND
U1 G1 is not driven
U1 G2 = VS1
U1 G2 = GND
U1 G2 is not driven
SHDN_1
LIM_1
Open
*Default
position.
4
______________________________________________________________________________________
MAX98400B Evaluation Kit
Evaluates: MAX98400B
Table 2. Jumper Descriptions (U2)
JUMPER
SHUNT
POSITION
1-2*
Open
Open*
TEMP_2
1-2
1-2*
2-3
DESCRIPTION
Normal operation; U2
SHDN
=
DVDD (external logic high)
Shutdown; U2
SHDN
= GND
Thermal foldback enabled; U2
TEMPLOCK = unconnected
Thermal foldback disabled; U2
TEMPLOCK = GND
Limiter disabled; U2 LIM_TH =
VS2
Limiter enabled in PVDD tracking
mode; U2 LIM_TH = GND
Limiter programmable mode; U2
LIM_TH is determined
by R203, R204, and R205
Single-ended input mode; U2
INL- = GND
Differential input mode; U2 INL-
is not connected to GND
Single-ended input mode; U2
INR- = GND
Differential input mode; U2 INR-
is not connected to GND
U2 G1 = VS2
U2 G1 = GND
U2 G1 is not driven
U2 G2 = VS2
U2 G2 = GND
U2 G2 is not driven
Table 3. Recommended EMI Filter
Components for 8I Loads
DESIGNATION
R111–R114
DESCRIPTION
600I at 100MHz, 150mI DCR,
2A ferrite beads (0805)
Würth Elektronik 742792040
330pF
Q10%,
50V X7R
ceramic capacitors (0603)
Murata GRM188R71H331K or
TDK C1608X7R1H331K
SHDN_2
C111–C114
Note:
3A current-rating ferrite beads are recommended for 4
I
load drive.
LIM_2
Table 4. Gain Jumper Descriptions*
SHUNT POSITION
GAIN1_1, GAIN1_2
2-3
Open
1-2
2-3
Open
1-2
2-3
Open
1-2
*GAIN1_1 and GAIN2_1 set the gain for U1.
GAIN1_2 and GAIN2_2 set the gain for U2.
1-2
Open
2-3
GAIN2_1, GAIN2_2
GAIN (dB)
9.0
13.0
16.7
20.1
23.3
26.4
29.8
32.9
Reserved
Open
1-2*
JU204
Open
1-2*
JU205
Open
1-2
GAIN1_2
2-3*
Open
1-2
GAIN2_2
*Default
position.
2-3
Open*
_______________________________________________________________________________________
5
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