MAX98357 Eval System 规格书

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Evaluates: MAX98357A/MAX98357B
(TQFN)
MAX98357 Evaluation System
(TQFN)
General Description
The MAX98357 development board (DEV board) is a fully
assembled and tested PCB that evaluates the MAX98357
I2S digital input Class D power amplifier. The DEV board
operates from a single 2.5V to 5.5V DC power supply and
is capable of delivering 3.2W into a 4Ω load. The device
outputs can be connected directly to a speaker load for
filterless applications. However, a filter can be added to
ease evaluation. The MAX98357A accepts standard I2S
data and the MAX98357B accepts left-justified digital
audio data. Both versions also support 8-channel TDM
audio data.
The MAX98357 evaluation system (EV system) includes
the MAX98357 DEV board and Maxim Integrated’s audio
interface board (MAXAUDINT001#).
The MAXAUDINT001# board provides an easy-to-use
USB audio-to-I2S converter. This allows for any computer
to become a digital audio source, which can be used to
evaluate the devices. The MAXAUDINT001# board can
also be used to power the MAX98357. This allows for a
complete evaluation from a single USB connection.
Features
●2.5V to 5.5V Single-Supply Operation
●Only a Single External Component (VDD Capacitor)
Required in Many Applications
●I2S, Left-Justified, or TDM Input
●Five Selectable Gains (3db, 6dB, 9dB, 12dB, and
15dB)
●Audio Channel Select (Left, Right, and Mono Mix)
●Filterless Operation
●Optional Class D Output Filters for Ease of
Evaluation
●Proven PCB Layout
●Fully Assembled and Tested
19-6843; Rev 3; 9/18
Ordering Information appears at end of data sheet.
Figure 1. Simplified Block Diagram
10µF 0.1µF
VDD GAIN
2.5V TO 5.5V
DAC
MAX98357
DIGITAL
AUDIO
INTERFACE
CLASS D
OUTPUT STAGE
OUTP
OUTN
AUDIO
INTERFACE
BOARD
LRCLK
PCM
BCLK
DIN
SD_MODE
Click here for production status of specific part numbers.
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Evaluates: MAX98357A/MAX98357B
(TQFN)
MAX98357 Evaluation System
(TQFN)
Quick Start
Recommended Equipment
• MAX98357 EV system
• 2.5V to 5.5V, 2A DC power supply
• USB audio source (from computer through an audio
media player such as iTunes® or Windows Media®
player)
• 4Ω or 8Ω speaker
Procedure
The EV system 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) On the DEV board verify that headers and switches
are configured as follows:
JU2: Pins 1-3 (selects left channel)
JU4: Pins 1-2 (power routed from the MAXAUDINT001#
board)
J
U5: Pins 1-5 (12dB gain)
JU6: Pins 2-3 (power routed from external supply)
SW1: Position 1-2 (part is on)
2) Set the power-supply output to 5V. Disable the power
supply.
3) Connect the power-supply ground terminal to GND
and the power-supply positive terminal to VIN on the
DEV board.
4) With the audio source disabled, connect the USB
audio source to the USB AUDIO port (USB2) on the
MAXAUDINT001# board.
5) Connect the MAXAUDINT001# board to J1 on the DEV
board.
6) Connect the speaker across the OUTP and OUTN test
points.
7) Enable the power-supply output.
8) Enable the audio source.
9) Verify that the speakers are playing the audio source
signal.
Detailed Description of Hardware
The MAX98357 EV system is designed to allow a
thorough evaluation of the MAX98357 I2S digital input
Class D power amplifier. The DEV board can be used by
itself as a stand-alone evaluation board and driven directly
by audio test equipment. The DEV board can also be used
in conjunction with the
MAXAUDINT001#
board, which
allows for any computer to become an I2S digital audio
source.
The MAXAUDINT001# board has DC regulators that can
be used to power the device. This allows for quick evalu-
ation from a single USB connection. Note that powering
the device from the MAXAUDINT001# board does not
allow for high-power evaluation as the input current is lim-
ited and evaluation with a speaker is not recommended.
Jumpers JU4 and JU6 are used to power the device from
the MAXAUDINT001# board or external supplies con-
nected to test points VIN and VDDIO on the DEV board.
The DEV board operates from a single 2.5V to 5.5V DC
power supply and is capable of delivering 3.2W into a 4Ω
load and 1.75W into an 8Ω load. The device outputs can
be connected directly to a speaker for filterless applica-
tions. However, a filter can be added to ease evaluation.
The LRC components needed for evaluation of a filtered
output are included with the EV kit. The MAX98357A
accepts standard I2S data and the MAX98357B accepts
left-justified digital audio data. Both versions also support
8-channel TDM audio data.
Filterless Output
The DEV board filterless outputs (OUTP, OUTN) can be
connected directly to a speaker load without any filter-
ing. Use the OUTP and OUTN test points to connect the
speaker directly to the device output.
Filtered Output
Audio analyzers typically cannot accept the Class D
amplifier’s pulse-width modulated (PWM) signals at their
inputs. Therefore, the DEV board features optional low-
pass filters at the outputs to ease evaluation. As shipped,
the DEV board’s lowpass filter LRC components are
unpopulated and L1, L2 are shorted on the PCB.
To use the filtered output posts (FOUTP, FOUTN), remove
the shorts on L1 and L2 and install components L1, L2,
C3–C7, and R5, R6. Use the output posts to connect the
filtered outputs to the audio analyzer. The default lowpass
filters at the DEV board output are optimized for a 4Ω
speaker.
iTunes is a registered trademark of Apple Inc.
Windows Media is registered trademark and registered service
mark of Microsoft Corporation.
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Evaluates: MAX98357A/MAX98357B
(TQFN)
MAX98357 Evaluation System
(TQFN)
EMI Considerations and Optional
Ferrite Bead Filter
In applications where speaker leads/wires are long
(exceeding approximately 12 inches), additional EMI sup-
pression can be achieved by using a filter constructed from
a ferrite bead (FB1, FB2) and a capacitor to ground (C8,
C9) (Figure 2). Use a ferrite bead with low DC resistance,
high-frequency impedance (> 600MHz) between 100Ω
and 600Ω, and rated for at least 1A-2A, depending on the
speaker impedance. The capacitor value varies based
on the ferrite bead chosen and the actual speaker lead
length. Select a capacitor less than 1nF with the value
based upon optimizing EMI performance. Although it
is best to choose filter components based on EMI test
results, the combination of 680pF capacitors (C8, C9) and
Murata BLM18SG331TN1 generally work well.
Do not use the optional ferrite bead filter in conjunction
with the optional Class D filter.
Jumper Selection
Selectable Gain (GAIN_SLOT)
The DEV board features a 5-pin jumper (JU5) to
control the device’s five programmable gain settings.
In TDM mode, the gain is fixed at 12dB and the gain pin is
repurposed for slot selection. See Table 1 for gain-control
configuration.
SD_MODE Input
The DEV board features a 4-pin jumper (JU2) to control
both the audio channel that is sent to the amplifier output,
along with shutdown mode. JU2 is used to select the
stereo input data between the left channel, right channel,
and the sum of the left/right channels. JU5 must be set to
pins 1-2 and a voltage applied to the +3.3V PCB pad for
proper operation. See Table 2 for shunt positions.
TDM Mode
In TDM mode, the device has a fixed gain of 12dB and
the gain pin becomes repurposed for slot selection. The
device accepts 8-channel TDM data. The data can be
either 16 bits or 32 bits wide. The GAIN_SLOT pin and
SD_MODE are used to select which of 8 channels of TDM
data the part responds to, as shown in Table 3.
Table 1. JU5 Jumper Selection
(GAIN_SLOT)
Table 2. JU2 Jumper Selection
(SD_MODE)
Table 3. TDM Mode Channel Selection
*Default position.
*Default position.
Figure 2. Optional Ferrite Bead Filter
SHUNT
POSITION GAIN PIN MAXIMUM
GAIN (dB)
1-2 Connected to VDD through
100kI resistor R1 3
1-3 Connected to VDD 6
1-4 Connected to GND through
100kΩ resistor R2 15
1-5* Connected to GND 12
Not installed Unconnected 9
SHUNT
POSITION SD_MODE PIN AUDIO
CHANNEL
1-2 Connected to VDDIO
through R3 (small resistor) Right
1-3* Connected to VDDIO
through a 2kΩ resistor Left
1-4 Connected to VDDIO
through R4 (large resistor)
Mono mix
(left + right)/2
JU2 JU5 CHANNEL BITS
Connected low X OFF N/A
(1-3) (1-5) 0 16 or 32
(1-3) (1-3) 1 16 or 32
(1-3) Open 2 16 or 32
(1-3) (1-2) 3 16 or 32
(1-3) (1-4) 4 16 or 32
(1-4) (1-5) 5 16 or 32
(1-4) Open 6 16 or 32
(1-4) (1-3) 7 16 or 32
MAX98357A
MAX98357B
OUTP
OUTN
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Evaluates: MAX98357A/MAX98357B
(TQFN)
MAX98357 Evaluation System
(TQFN)
Shutdown Mode
The device features a low-power shutdown mode that is
activated by setting jumper SW1 to pins 2-3. To exit shut-
down mode, set SW1 to pins 1-2 and select the desired
stereo input channel using jumper JU2. See Table 4 for
switch positions.
External/Internal VDDIO (+1.8V to +3.3V)
On the DEV board, a logic voltage from a control interface
is needed for proper selection of the stereo input channel
through SD_MODE. This voltage can be applied exter-
nally at the VDDIO test point or it can be provided from
circuitry on the MAXAUDINT001# board. See Table 5 for
JU4 jumper selection.
Logic voltages other than +3.3V can be used. If you want
to use other logic voltages, resistors R3 and R4 must
be adjusted. Refer to the SD_MODE and Shutdown
Operation section in the MAX98357 IC data sheet for
more information.
VDD Input Supply (+2.5V to +5.5V)
The device can accept an input supply from +2.5V to
+5.5V. This voltage can be applied externally at the
VDD and GND PCB pads, or it can be provided from the
MAXAUDINT001# board. See Table 6 for JU6 jumper
selection.
Audio Interface Board (MAXAUDINT001# Board)
The MAXAUDINT001# board provides USB-to-I2S data
conversion, as well as DC regulators that can be used
to power the devices. The USB-to-I2S converter on the
MAXAUDINT001# board allows for any computer to
become an I2S digital audio source without requiring
additional driver installation. On the MAXAUDINT001#
board, set SW1 to “demo” and set the I2S switch to con-
nected to source audio by USB. This allows for a quick
evaluation from a single USB connection. Using the
MAXAUDINT001# board as a power supply for high-pow-
er evaluation is not recommended as the input current is
limited. For high-power evaluation, use an external supply
connected to VIN.
Driving I2S Directly
To drive I2S directly, apply signals at the BCLK, LRCLK,
and SDIN test points, or on the J3 header, or between J3
pins 1-2 at the appropriate locations (signal and ground
are labeled on the board).
Evaluating the MAX98357B
The MAX98357 DEV board comes with a MAX98357A
populated on the board, but can be used to evaluate
the MAX98357B. To evaluate the MAX98357B, carefully
remove the MAX98357A (U1) device from the board and
replace with MAX98357BETE+. No other component
changes are required.
Table 5. JU4 Jumper Selection (VDDIO)
Table 6. JU6 Jumper Selection (VDD)
*Default position.
*Default position.
Table 4. SW1 Switch Configuration
*Default position.
SHUNT
POSITION LOGIC VOLTAGE (VDDIO)
1-2* 3.3V supplied by the MAXAUDINT001#
board connected to J1 header.
2-3 User-supplied external power supply applied
at the VDDIO test point.
SHUNT
POSITION INPUT VOLTAGE (VDD)
1-2* VDD supplied from the MAXAUDINT001#
board connected to the J1 header.
2-3 User-supplied external power supply applied
at the VIN PCB pad.
SWITCH
POSITION
VDDIO
VOLTAGE
DEVICE
OPERATION
1-2*
VDDIO determined
by JU4 jumper
position
Normal
(input channel selected
through JU2 setting)
2-3 Connected to GND Shutdown
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Evaluates: MAX98357A/MAX98357B
(TQFN)
MAX98357 Evaluation System
(TQFN)
Note: Indicate that you are using the MAX98357A/MAX98357B TQFN when contacting these component suppliers.
DESIGNATION QTY DESCRIPTION
BCLK, DIN,
LRCLK 3Orange multipurpose test
points
C1 1
10µF ±10%, 6.3V X5R ceramic
capacitor (0603)
Murata GRM188R60J106K
C2 1
0.1µF ±10%, 16V X7R ceramic
capacitor (0402)
Murata GRM155R71C104K
C3–C12 0 Not installed, ceramic capaci-
tors (0402)
C11 1
22pF ±5%, 50V C0G ceramic
capacitor (0402)
Murata GRM1555C1H220J
FB1, FB2 2 0Ω ±5% resistors (0603)
FOUTN, FOUTP,
GND, VIN 4 Binding posts
FOUTN, FOUTP,
GND (x2), VDD 5
20G plated solid copper bus
wire, 0.25in U-shaped wire
loop
GND (x4), OUTN 5 Black multipurpose test points
(63 mil drill size)
J1 1 26-pin (2 x 13) dual-row right-
angle header, 0.1in centers
J3 1 6-pin header
JU2 1 4-pin header, 0.1 in centers
JU4, JU6 2 3-pin headers, 0.1 in centers
JU5 1 5-pin header, 0.1 in centers
L1, L2 0
Not installed, 22µH inductors
(6.2mm x 6.3mm)—short
(PC trace)
TOKO D63CB series part
TOKO A916CY-220M
OUTP 1 White multipurpose test point
(63 mil drill size)
DESIGNATION QTY DESCRIPTION
R1, R2 2 100kΩ ±5% resistors (0603)
R3 1 226kΩ ±1% resistor (0603)
R4 1 634kΩ ±1% resistor (0603)
R5, R6 0 Not installed, resistors (0402)
R7–R9 3 0Ω ±5% resistors (0603)
SW1 1 SPDT jumper switch, 0.1in
centers
U1 1
I2S input Class D audio
amplifier (16 TQFN)
Maxim MAX98357AETE+
VDDIO 1 Red multipurpose test point
(63 mil drill size)
— 4 Shunts
— 1 PCB: MAX98357 TQFN EVKIT
DEVELOPMENT BOARD
OPTIONAL CLASS D FILTER COMPONENTS
C3–C7 7
0.22µF ±10%, 6.3V X5R ce-
ramic capacitors (0402)
TDK C1005X5R0J224K
L1, L2 2
22µH, 1A inductors
(6.2mm x 6.3mm)
TOKO A916CY-220M
R5, R6 2 22Ω ±5% resistors (0402)
OPTIONAL I2S CONDITIONING COMPONENTS
C10–C12 2 18pF ±5%, 50V C0G ceramic
capacitors (0402)
R7–R9 3 51Ω ±5% resistors (0402)
OPTIONAL EMI FILTERING COMPONENTS
C8, C9 2
680pF ±10% 50V X54 ceramic
capacitors (0402) TDK
CGA2B1C0G2A681J050BE
FB1, FB2 2 Murata BLM18SG331TN1
(0603)
SUPPLIER PHONE WEBSITE
Murata Americas 770-436-1300 www.murataamericas.com
TDK Corp. 847-803-6100 www.component.tdk.com
TOKO America, Inc. 847-297-0070 www.tokoam.com
Component Suppliers
Component List
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Evaluates: MAX98357A/MAX98357B
(TQFN)
MAX98357 Evaluation System
(TQFN)
Figure 3. MAX98357 DEV Board Schematic
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Evaluates: MAX98357A/MAX98357B
(TQFN)
MAX98357 Evaluation System
(TQFN)
MAX98357 DEV Board Silkscreen—Top
MAX98357 DEV Board PCB Layout—Layer 2
MAX98357 DEV Board PCB Layout—Component Side
1.0”
1.0”
1.0”
MAX98357 EV Kit PCB Layouts
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Evaluates: MAX98357A/MAX98357B
(TQFN)
MAX98357 Evaluation System
(TQFN)
#Denotes a RoHS-compliant device that may include lead(Pb)
that is exempt under the RoHS requirements.
MAX98357 DEV Board PCB Layout—Solder SideMAX98357 DEV Board PCB Layout—Layer 3
MAX98357 EV Kit PCB Layouts (continued)
PART TYPE
MAX98357DEV#TQFN Development Board
(DEV Board only)
MAX98357EVSYS#TQFN Evaluation System
(DEV + Boards)
1.0”
Ordering Information
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2018 Maxim Integrated Products, Inc.
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Evaluates: MAX98357A/MAX98357B
(TQFN)
MAX98357 Evaluation System
(TQFN)
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 11/13 Initial release —
1 4/14 Added Evaluating the MAX98357B section, moved VDDIO to new pin on J1, added a
22pF capacitor to C11, and updated Figures 2 and 6 4–6, 8
2 9/18
Changed all instances of “AUDINT001” to “MAXAUDINT,” added EMI Considerations
and Optional Ferrite Bead Filter section, added new Figure 2, updated Table 6 title,
updated Component List table
1–8
3 9/18
Changed all instances of “MAXAUDINT” to “MAXAUDINT001#,” added EMI filtering
information to the EMI Considerations and Optional Ferrite Bead Filter section,
updated Component List and Ordering Information table
1–5, 8
Revision History
For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html.