MAX9700D [MAXIM]
Selectable Switching Frequency;
| 型号： | MAX9700D |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Selectable Switching Frequency |
| 文件： | 总5页 (文件大小：755K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-3248; Rev 0; 4/04
MAX9700B Evaluation Kit
General Description
Features
The MAX9700B evaluation kit (EV kit) is a fully assembled
and tested circuit board that uses the MAX9700B filter-
less 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
is capable of delivering 1.2W into an 8Ω load.
♦ Filterless Operation Passes FCC Radiated
Emissions
♦ Evaluates the MAX9700A/B/C/D or MAX9712 (with
IC Replacement)
♦ 2.5V to 5.5V Single-Supply Operation
♦ Up to 94% Efficiency
♦ Drives 1.2W into 8Ω Speaker at 1% THD+N
♦ Differential or Single-Ended Inputs
♦ Selectable Switching Frequency
♦ 0.1µA Shutdown Current
The EV kit accepts differential or single-ended input
signals. The EV kit provides an option to select between
different switching frequency modes of operation. The
MAX9700B EV kit also evaluates the MAX9700A/
MAX9700C/MAX9700D and the MAX9712.
♦ Small 10-Pin TDFN Package
Ordering Information
♦ Also Available in 10-Pin µMAX and 12-Bump
PART
MAX9700BEVKIT
TEMP RANGE
0°C to +70°C
IC PACKAGE
10 TDFN-EP*
UCSP™ Packages
*EP = Exposed paddle.
♦ Fully Assembled and Tested
UCSP is a trademark of Maxim Integrated Products, Inc.
Component List
DESIGNATION QTY
DESCRIPTION
DESIGNATION QTY
DESCRIPTION
3-pin header
JU1
JU2
JU3
1
1
1
Not installed, MAX9700BEUB
(10-pin µMAX)
A1
A2
0
0
5-pin header
2-pin header
Not installed, MAX9700BEBC-T
(12-bump UCSP)
Not installed, inductors
recommended
TOKO D53LC series
L1, L2
0
3
0.1µF 10ꢀ, 25V X7ꢁ ceramic
capacitors (0603)
TDK C1608X7ꢁ1E104K
C1, C2
2
Ferrite beads 100Ω at 100MHz,
50mΩ DCꢁ, 3A (0603)
TDK MPZ1608S101A
L3, L4, L5
10µF 20ꢀ, 6.3V X5ꢁ ceramic
capacitor (0805)
TDK C2012X5ꢁ0J106M
C3
C4
1
0
2
ꢁ1
1
0
49.9Ω 1ꢀ resistor (0603)
Not installed, capacitor (0805)
ꢁ2, ꢁ3
Not installed, resistors (0603)
1µF 10ꢀ, 10V X5ꢁ ceramic
capacitors (0603)
TDK C1608X5ꢁ1A105K
Not installed, common-mode choke
50VDC, 1ADC 800Ω at 100MHz
recommended
C5, C6
T1
0
TDK ACM4532-801-2P-X
C7, C8, C9,
C11–C14
0
1
Not installed, capacitors (0603)
MAX9700BETB
(10-pin TDFN, 3mm x 3mm x 0.8mm))
U1
1
100pF 5ꢀ, 50V C0ꢂ ceramic
capacitor (0603)
TDK C1608C0ꢂ1H101J
None
None
3
1
Shunts (JU1, JU2, JU3)
MAX9700B PC board
C10
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MAX9700B Evaluation Kit
Component Suppliers
SUPPLIER
PHONE
FAX
WEBSITE
www.component.tdk.com
www.tokoam.com
TDK
847-803-6100
847-297-0070
847-390-4405
847-699-1194
TOKO
Note: Please indicate that you are using the MAX9700B when contacting these component suppliers.
short T1-1 to T1-4, and short T1-2 to T1-3. See Table 1
Quick Start
for the suggested filtering component values for an 8Ω
The MAX9700B EV kit is fully assembled and tested.
Follow the steps listed below to verify board operation.
Do not turn on the power supply until all connec-
tions are completed.
load and a 30kHz cutoff frequency.
Table 1. Suggested Filtering Components
for an 8Ω Load and 30kHz Cut-Off
Recommended Equipment:
• 2.5V to 5.5V, 1A power supply
COMPONENT
VALUE
L1, L2
15µH
• Audio source (i.e. CD player, cassette player)
C7, C8
0.033µF
0.15µF
0.068µF
22Ω
• 8Ω speaker
C9
Procedures:
1) Install a shunt across pins 1 and 2 of jumper JU1
(EV kit ON).
C13, C14
ꢁ2, ꢁ3
2) Install a shunt across pins 1 and 2 of jumper JU2
(internal oscillator set to spread-spectrum mode).
3) Verify that no shunt is across jumper JU3 (differen-
tial input mode).
The MAX9700B is designed to pass FCC Class-B ꢁF
emissions without additional filtering when using 10cm of
cable to connect the speaker. In applications where more
margin and/or cable length are required, output capaci-
tors C11, C12 and common-mode choke T1 can be
added to reduce radiated emission. Connect the speaker
to output +/- test points. Table 2 lists the cable length
verses the required output components.
4) Connect the 8Ω speaker across the OUT+ and
OUT- test points.
5) Connect the positive terminal of the power supply to
the VDD pad and the power-supply ground terminal
to the ꢂND pad.
Table 2. Cable Length vs. Suggested
Output Components
6) Connect the audio source across the INPUT+ and
INPUT- pads.
7) Turn on the power supply.
8) Turn on the audio source.
LCR FILTER
CABLE
LENGTH X
(CM)
OUTPUT
COMMON-
MODE
L1, L2, C7, C8,
C9, C13, C14,
R2, R3
CAPACITOR
C11 AND C12
Detailed Description
CHOKE T1
The MAX9700B EV kit features the MAX9700B filterless
class D amplifier IC, designed to drive a BTL mono
speaker in portable audio applications. The EV kit oper-
ates from a DC power supply that can provide 2.5V to
5.5V and 1A of current. The EV kit accepts a differential
or single-ended audio input. The audio input source is
amplified to drive 1.2W into an 8Ω speaker.
The EV kit provides three sets of differential outputs.
The device outputs (OUT+/-) can be connected directly
to a speaker load without any filtering. However, a filter
can be added to ease evaluation. The filtered outputs
(FOUTPUT+/-) require installation of filtering compo-
nents L1, L2, C7, C8, C9, C13, C14, ꢁ2, and ꢁ3. When
an LCꢁ filter is required, remove C11, C12, and T1,
X < 10
—
—
—
—
—
10 < X < 15 ꢁequired (100pF)
15 < X < 30 ꢁequired (100pF) ꢁequired
X > 30
—
—
—
ꢁequired*
*When an LCR filter is required, remove C11, C12 and T1, short
T1-1 to T1-4, short T1-2 to T1-3.
2
_______________________________________________________________________________________
MAX9700B Evaluation Kit
Input Mode
Jumper JU3 provides an option to select between a
differential or single-ended input mode for the EV kit.
See Table 5 for shunt positions.
Jumper Selection
Shutdown Mode (SHDN)
Jumper JU1 controls the shutdown pin (SHDN) of the
MAX9700B IC. See Table 3 for shunt positions.
Table 3. JU1 Jumper Selection
Table 5. JU3 Jumper Selection
SHUNT POSITION
EV KIT INPUT MODE
SHUNT POSITION
1-2 (SHDN = high)
2-3 (SHDN = low)
EV KIT FUNCTION
EV kit enabled
None
(default)
Differential Input Mode
Shutdown mode
Installed
(IN- pad connected to ꢂND)
None. External
controller connected to
SHDN pad (TTL).
Single-Ended Input Mode
SHDN driven by external controller.
Shutdown is active low.
Evaluating the MAX9700A/MAX9700C/MAX9700D
and the MAX9712
Switching Frequency Mode (Sync)
Jumper JU2 provides an option to select the switching
frequency of the MAX9700B IC. See Table 4 for the
various shunt positions.
The MAX9700B EV kit can evaluate the MAX9700A,
MAX9700C, MAX9700D, and the MAX9712. To evalu-
ate a different IC, replace U1 with the desired part.
ꢁefer to the MAX9700 or the MAX9712 data sheets for
additional information.
Table 4. JU2 Jumper Selection
INTERNAL
OSCILLATOR
FREQUENCY
SHUNT
POSITION
MAX9700B SYNC
PIN
Spread-Spectrum Mode.
Set at a switching
1-2
(default)
SYNC pin = high
frequency f
=
SW
1.22MHz ±120kHz
1-3
1-4
1-5
SYNC pin = floating
SYNC pin = external
TTL-compatible clock Synchronized to the
input. External clock
input connected to
SYNC (TTL).
Set at f = 1.45MHz
NOM
incoming TTL-compatible
clock frequency
Set at the nominal
SYNC = low
_______________________________________________________________________________________
3
MAX9700B Evaluation Kit
L5
FERRITE
VDD
1
10
7
V
PV
DD
DD
C1
0.1µF
C2
0.1µF
C3
10µF
C4
OPEN
R2
OPEN
GND
4
2
3
PGND
OUT-
GND
IN+
C13
OPEN
L3
FERRITE
INPUT+
INPUT-
L2
OPEN
9
U1
T1
OPEN
C5
1.0µF
L4
FERRITE
C8
OPEN
C11
OPEN
1
2
4
MAX9700B
OUT-
OUT+
C9
OPEN
OUTPUT-
OUTPUT+
FOUTPUT-
FOUTPUT+
IN-
C6
1.0µF
3
JU3
8
VDD
OUT+
L1
OPEN
C7
OPEN
C12
OPEN
C14
OPEN
JU1
1
SHDN
5
6
2
SHDN
SYNC
R3
OPEN
3
VDD
C10
100pF
JU2
4
3
2
SYNC
1
5
R1
49.9Ω
1%
Figure 1. MAX9700B EV Kit Schematic
Figure 2. MAX9700B EV Kit Component Placement Guide—
Component Side
Figure 3. MAX9700B EV Kit PC Board Layout—Component
Side
4
_______________________________________________________________________________________
MAX9700B Evaluation Kit
Figure 4. MAX9700B EV Kit PC Board Layout—GND Layer 2
Figure 5. MAX9700B EV Kit PC Board Layout—GND Layer 3
Figure 6. MAX9700B EV Kit PC Board Layout—Solder Side
Figure 7. MAX9700B 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 _____________________ 5
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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