General Description
The MAX13331 evaluation kit (EV kit) is a fully assem-
bled and tested surface-mount circuit board that evalu-
ates the MAX13331 DirectDrive®stereo headphone
amplifier. DirectDrive eliminates the two large DC-
blocking capacitors typically required between the out-
put of the amplifier and the headphones. The
MAX13331 EV kit includes two RCA phono jacks on the
input and a 3.5mm headphone jack on the output to
facilitate easy connections to the circuit board.
The MAX13331 EV kit can also evaluate the MAX13330
IC. This requires the IC replacement of U1.
Features
♦No DC-Blocking Capacitors Required
♦4V to 5.5V Single-Supply Operation
♦Adjustable Gain (MAX13331 Only)
♦125mW Per Channel into 32Ωat 0.01% THD+N
♦Shutdown Control
♦Ultra-Compact Solution
♦Low-Profile (1.2mm, max) Design
♦Lead(Pb)-Free and RoHS Compliant
♦Fully Assembled and Tested Surface-Mount Board
Evaluates: MAX13330/MAX13331
MAX13331 Evaluation Kit
________________________________________________________________
Maxim Integrated Products
1
19-4499; Rev 1; 4/09
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.
Ordering Information
PART TYPE
MAX13331EVKIT+ EV Kit
+
Denotes lead(Pb)-free and RoHS compliant.
Component List
DESIGNATION QTY DESCRIPTION
C1, C2 2
1µF ±10%, 16V X7R ceramic
capacitors (0603)
Murata GRM188R71C105K
TDK C1608X7R1C105K
C3, C4, C11 3
1000pF ±10%, 50V X7R ceramic
capacitors (0402)
Murata GRM155R71H102K
TDK C1005X7R1H102K
C5, C7, C8 3
1µF ±10%, 10V X7R ceramic
capacitors (0603)
Murata GRM188R71A105K
TDK C1608X7R1A105K
C6, C9, C14 3
0.1µF ±10%, 16V X7R ceramic
capacitors (0402)
Murata GRM155R71C104K
TDK C1005X7R1C104K
C10 1
10µF ±10%, 10V X7R ceramic
capacitor (0805)
Murata GRM21BR71A106K
C12, C13 2
0.01µF ±10%, 50V X7R ceramic
capacitors (0402)
Murata GRM155R71H103K
DESIGNATION QTY DESCRIPTION
J1 1 3.5mm stereo headphone jack
JU1 1 2-pin header, 0.1in centers
JU2 0 Not installed, 2-pin header, 0.1in
centers
OUTL, OUTR,
SGND 0 Not installed, miniature test points
P1 1 RCA phono jack (side-entry PCB
mount), white
P2 1 RCA phono jack (side-entry PCB
mount), red
R1, R2, R5 3 15kΩ ±1% resistors (0402)
R3, R4 2 22.6kΩ ±1% resistors (0402)
U1 1
Automotive DirectDrive headphone
amplifier (16 QSOP)
Maxim MAX13331GEE/V+
— 1 Shunt
— 1 PCB: MAX13331 EVALUATION KIT+
DirectDrive is a registered trademark of Maxim Integrated
Products, Inc.
Evaluates: MAX13330/MAX13331
Quick Start
Required Equipment
• One pair of 8Ωto 32Ωheadphones
• One variable DC power supply capable of supply-
ing between 4V and 5.5V at 500mA
• One stereo audio source
Procedure
The MAX13331 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) Plug the headphones into the 3.5mm headphone
jack (J1).
2) Ensure that the stereo audio source is turned off.
3) Connect the disabled stereo audio source through
the RCA phono jacks (P1 and P2).
4) Ensure that a shunt is installed on jumper JU1.
5) Connect the 4V to 5.5V DC power supply to the
VDD and PGND pads.
6) Turn on the DC power supply.
7) Verify that the audio source level is low.
8) Enable the stereo audio source.
9) Verify that the audio source signal is clearly heard
from the headphones.
Detailed Description of Hardware
The MAX13331 EV kit is a stereo, single-supply head-
phone amplifier. The input impedance is 15kΩ. The
-3dB corner frequencies are approximately 10Hz and
greater than 22kHz and are dependent on components
R1/C1 and R2/C2. The MAX13331 EV kit has a gain of
approximately 1.5 and can be powered with a 4V to
5.5V supply
The EV kit provides two RCA phono jacks (P1 and P2)
to facilitate the connection of an audio source. In addi-
tion, both outputs (OUTL and OUTR) are routed to a
stereo headphone jack (J1), facilitating output monitor-
ing. Shutdown control of OUTL and OUTR is also pro-
vided through jumper JU1.
Shutdown Control
The MAX13331 EV kit provides jumper JU1 to disable
the outputs, OUTL and OUTR (see Table 1 for shut-
down shunt positions). Both OUTL and OUTR are rout-
ed to the headphone jack (J1).
Layout Considerations
To optimize the audio performance of the MAX13331, it is
important to follow these layout guidelines. The MAX13331
EV kit uses two ground planes to minimize switching noise.
The two planes are star-connected at one point (JU2 pad).
Capacitors C5, C6, C8, C12, C13, and C14 should be
placed close to the IC. Refer to the MAX13331 IC data
sheet for additional layout considerations.
The MAX13331 EV kit is a four-layer design, but it is
possible to design the MAX13331 circuit on to a two-
layer board. For a two-layer design, optimize the signal
and power ground planes by maximizing the area and
connecting each plane, as close as possible, to its
respective IC pin.
MAX13331 Evaluation Kit
2 _______________________________________________________________________________________
SUPPLIER PHONE WEBSITE
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
TDK Corp. 847-803-6100 www.component.tdk.com
Component Suppliers
Note: Indicate that you are using the MAX13331 when contacting these component suppliers.
Table 1. Jumper JU1 Function
SHUNT POSITION DESCRIPTION
Installed Outputs enabled
Not installed Outputs disabled
Evaluates: MAX13330/MAX13331
MAX13331 Evaluation Kit
_______________________________________________________________________________________ 3
Figure 1. MAX13331 EV Kit Schematic
Evaluates: MAX13330/MAX13331
MAX13331 Evaluation Kit
4 _______________________________________________________________________________________
Figure 2. MAX13331 EV Kit Component Placement Guide—Component Side
Figure 3. MAX13331 EV Kit PCB Layout—Component Side
Evaluates: MAX13330/MAX13331
MAX13331 Evaluation Kit
_______________________________________________________________________________________ 5
Figure 4. MAX13331 EV Kit PCB Layout—Internal Layer 2
Figure 5. MAX13331 EV Kit PCB Layout—Internal Layer 3
Evaluates: MAX13330/MAX13331
MAX13331 Evaluation Kit
6 _______________________________________________________________________________________
Figure 6. MAX13331 EV Kit PCB Layout—Solder Side
Figure 7. MAX13331 EV Kit Component Placement Guide—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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________
7
© 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Evaluates: MAX13330/MAX13331
MAX13331 Evaluation Kit
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 3/09 Initial release —
1 4/09 Updated schematic and PCB layout diagrams with routing changes on jacks P1 and
P2 3–6
