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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.
MAX98500 Evaluation Kit
Evaluates: MAX98500
General Description
The MAX98500 evaluation kit (EV kit) is a fully assembled
and tested circuit board that uses the MAX98500 boost-
ed Class D amplifier to drive a mono bridge-tied-load
(BTL) speaker in portable audio applications. Designed
to operate from a 2.5V to 5.5V DC power supply, the EV
kit delivers 2.2W into an 8I load. The EV kit accepts
differential or single-ended input signals, features three
selectable gain settings (6dB, 15.5dB, and 20dB), and
provides separate speaker and boost shutdown inputs.
Features
S 2.5V to 5.5V Single-Supply Operation
S Output Power: 2.2W into 8ω, 10% THD+N
S Selectable Gain Settings (6dB, 15.5dB, and 20dB)
S Boosted Class D Output
S Differential or Single-Ended Input Signals
S Boost Converter Shutdown
S Speaker Output Shutdown
S Fully Assembled and Tested
Ordering Information
Component List
19-5221; Rev 0; 5/10
+Denotes lead(Pb)-free and RoHS compliant.
PART TYPE
MAX98500EVKIT+ EV Kit
DESIGNATION QTY DESCRIPTION
REQUIRED COMPONENTS
C1 1
10FF Q10%, 6.3V X7R ceramic
capacitor (0805)
Murata GRM21BR70J106K
TDK C2012X7R0J106K
C2 1
22FF Q20%, 16V X5R ceramic
capacitor (1206)
Murata GRM31CR61226M
Taiyo Yuden EMK316BJ226M
C3, C4 2
1FF Q10%, 25V X7R ceramic
capacitors (0603)
Murata GRM188R71E105K
Murata GRM188R71E105M
C5 1
22FF Q10%, 6.3V X5R ceramic
capacitor (0805)
Murata GRM21BR60J226M
TDK C2012X5R0J226K
C8 1
0.1FF Q10%, 16V X7R ceramic
capacitor (0402)
Murata GRM155R71C104K
TDK C1005X7R1C104K
C9, C10 0 Not installed, ceramic capacitors
(0402)
C12, C13 0 Not installed, ceramic capacitors
(0603)
DESIGNATION QTY DESCRIPTION
C14–C18 5
0.22FF Q10%, 25V X7R ceramic
capacitors (0603)
Murata GRM188R71E224K
TDK C1608X7R1E224K
FB1 1 0I resistor (0603)
FB2, FB3 0 Not installed, ferrite beads (0603)
J1 1 Phono jack, black (side-entry
PCB mount)
JU1, JU2, JU3 3 3-pin headers
JU4 1 2-pin header
L1 1
2.2FH, 34mI, 4.5A inductor
TOKO FDV0530S-2R2M
(5mm x 5mm x 3mm)
TDK LTF5022T-2R2N3R2-LC
(5mm x 5mm x 2.2mm)
NEC MPLC0525L2R2
(5.2mm x 6.2mm x 2.5mm)
L2, L3 0
Not installed, inductors
TOKO A916CY-220M (provided
with EV kit)
OUT-, OUT+,
PGND, RKNEE 4 Test points
R1 1 27.4kω Q1% resistor (0603)
R2, R3 2 22ω Q5% resistors (0603)
MAX98500 Evaluation Kit
Evaluates: MAX98500
2 ______________________________________________________________________________________
Quick Start
Recommended Equipment
• 2.5Vto5.5V,4ADCpowersupply
• 8I speaker
• Monoaudiosignalsource
Procedure
The MAX98500 EV kit is fully assembled and test-
ed. Follow the steps below to verify board operation.
Caution: Do not turn on the power supply until all
connections are completed.
1) Verify that shunts are installed as follows:
JU1: Open (15.5dB gain)
JU2: Pins 1-2 (speaker enabled)
JU3: Pins 1-2 (boost enabled)
JU4: Short (single-ended/unbalanced input)
2) Set the power-supply output to 3.6V.
3) Disable the power-supply output.
4) Connect the power-supply ground to the PGND pad
and the power-supply positive output to the VBAT
pad on the EV kit. Keep VBAT lengths < 6in and
twisted to minimize inductance, to ensure proper
device operation.
5) Verify that the audio source output is disabled.
6) Connect the mono audio source between the IN+
and IN- pads or J1 on the EV kit.
7) Connect the speaker across the OUT+ and OUT-
test points.
8) Enable the power-supply output.
9) Enable the audio source.
10) Verify that the speaker is playing the audio source
signal.
Detailed Description of Hardware
The MAX98500 EV kit features the MAX98500 boosted
Class D amplifier IC, designed to drive a BTL mono
speaker in portable audio applications. The EV kit
accepts a differential or single-ended audio input, fea-
tures three selectable gain settings (6dB, 15.5dB, and
20dB), and provides two active-low shutdown inputs for
flexibility. The audio input source is amplified to drive
2.2W into an 8I speaker. The EV kit operates from a
single DC power supply that provides 2.5V to 5.5V.
The EV kit provides two sets of differential outputs. The
device outputs (OUT+ and OUT-) can be connected
directly to a speaker load without any filtering. However,
a filter can be added to ease evaluation.
Component List (continued)
Component Suppliers
Note: Indicate that you are using the MAX98500 when contacting these component suppliers.
DESIGNATION QTY DESCRIPTION
U1 1
Boosted Class D amplifier
(16 WLP)
Maxim MAX98500EWE+
VCCOUT 0 Not installed, test point
— 4 Shunts
— 1 PCB: MAX98500 EVALUATION
KIT+
DESIGNATION QTY DESCRIPTION
OPTIONAL COMPONENTS
L2, L3 2
22FH Q20%, 0.7A inductors
(D63CB)
TOKO A916CY-220M
SUPPLIER PHONE WEBSITE
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
NEC TOKIN America, Inc. 408-324-1790 www.nec-tokinamerica.com
TDK Corp. 847-803-6100 www.component.tdk.com
TOKO America, Inc. 847-297-0070 www.tokoam.com
MAX98500 Evaluation Kit
Evaluates: MAX98500
_______________________________________________________________________________________ 3
*Default position.
*Default position.
*Default position.
Selectable Gain Setting
The MAX98500 features three internal gain settings that
are selectable with the GAIN input. Jumper JU1 controls
the amplifier’s gain select input. See Table 1 for jumper
JU1 configuration.
Shutdown Inputs
The MAX98500 features two active-low shutdown inputs
(SDSPK and SDBST). Jumper JU2 enables or disables
the speaker amplifier (SDSPK) and jumper JU3 controls
the boost converter (SDBST). See Table 2 for jumpers
JU2 and JU3 configuration. Note that the boost must be
enabled for the speaker amplifier to enable.
Input Mode
Jumper JU4 provides the option to select between a dif-
ferential or single-ended input mode for the EV kit. See
Table 3 for JU4 configuration.
Optional Output Filtering
The MAX98500 speaker amplifier is designed to pass
FCC emissions standards without any filtering. When
evaluating the MAX98500 without any filtering, connect
the speaker to the output test points (OUT+, OUT-).
The EV kit also features PCB pads for a lowpass filter
that can be added to ease evaluation. Audio analyzers
typically cannot accept the Class D amplifier’s pulse-
width-modulated (PWM) waveform at their inputs. The
lowpass filter extracts the audio content from the PWM
output signal and allows the device to be connected
directly to an audio analyzer. The PWM output signal
can be lowpass-filtered by simply installing L2 and L3;
all other components are populated. The filtered outputs
should then be monitored at the FOUT+/FOUT- pads.
See Table 4 for suggested filtering components for an
8I load.
Table 1. Gain Input (JU1) Table 3. Input Mode (JU4)
Table 2. Shutdown Configuration
(JU2, JU3) Table 4. Suggested Filtering Components
for 8I Load
SHUNT
POSITION GAIN PIN GAIN SETTING
(dB)
2-3 Connected to AGND 6
Not installed* Unconnected 15.5
1-2 Connected to VBAT 20
SHUNT
POSITION IN- PIN INPUT MODE
Installed* Connected to AGND Single-ended/
unbalanced input
Not installed
Connected to user-
supplied negative
differential output
Differential input
SDSPK PIN
(JU2)
SDBST PIN
(JU3)
BOOST
STATUS
SPEAKER
STATUS
2-3 (low) 2-3 (low) Off Off
1-2 (high) 2-3 (high) Off Off
2-3 (low) 1-2 (low) On Off
1-2* (high) 1-2* (high) On On
DESIGNATION QTY DESCRIPTION
L2, L3 2
22FH Q20%, 0.7A inductor
(D63CB)
TOKO A916CY-220M
MAX98500 Evaluation Kit
Evaluates: MAX98500
4 ______________________________________________________________________________________
Figure 1. MAX98500 EV Kit Schematic
MAX98500 Evaluation Kit
Evaluates: MAX98500
_______________________________________________________________________________________ 5
Figure 2. MAX98500 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX98500 EV Kit PCB Layout—Component Side
Figure 4. MAX98500 EV Kit PCB Layout—Solder Side
1.0”
1.0”
1.0”
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.
6 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.
MAX98500 Evaluation Kit
Evaluates: MAX98500
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 5/10 Initial release —
