General Description
The MAX8727 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that contains a
pulse-width-modulated (PWM) step-up DC-DC convert-
er. The EV kit is configured to operate with a 1.2MHz
switching frequency. It operates from a 2.6V to 5.5V DC
supply voltage, is configured for a 15V output, and can
provide 600mA with a 4.5V input.
The MAX8727 EV kit features low quiescent current and
high conversion efficiency (90%). The high switching
frequency allows for the use of small surface-mount
components.
Features
♦90% Efficiency
♦2.6V to 5.5V Input Range
♦15V Output Voltage (Adjustable from VIN to 24V)
♦600mA Output Current (4.5V Input)
♦1.2MHz Switching Frequency (Selectable: 640kHz
or 1.2MHz)
♦Programmable Soft-Start
♦0.1µA IC Shutdown Current (typ)
♦Fully Assembled and Tested
Evaluates: MAX8727
MAX8727 Evaluation Kit
________________________________________________________________ Maxim Integrated Products 1
19-3616; Rev 0; 3/05
Component List
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.
Ordering Information
PART
TEMP RANGE
IC PACKAGE
MAX8727EVKIT
0°C to +70°C
10 TDFN (3mm x 3mm)
DESIGNATION QTY DESCRIPTION
C1 0 Not installed, ceramic capacitor
(0805)
C2 1
10µF ±10%, 6.3V X5R ceramic
capacitor (0805)
Murata GRM21BR60J106K
Taiyo Yuden JMK212BJ106K
C3 1
1µF ±10%, 6.3V X5R ceramic
capacitor (0603)
Murata GRM188R60J105K
C4 1
0.033µF ±10%, 25V X7R ceramic
capacitor (0603)
Murata GRM188R71E333K
C5 1
330pF ±10%, 50V X7R ceramic
capacitor (0603)
Murata GRM188R71H331K
C6 1
39pF ±5%, 50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H390J
Taiyo Yuden UMK107CG390JZ
C7, C8, C9 3
4.7µF ±20%, 25V X7R ceramic
capacitors (1206)
Murata GRM31CR71E475M
Taiyo Yuden TMK316BJ475KL
DESIGNATION QTY DESCRIPTION
C10 1
100µF ±20%, 6.3V aluminum
electrolytic capacitor
(SMT: 6.3mm x 6.0mm)
Sanyo 6CV100AX
D1 1 3A, 30V Schottky diode (M-flat)
Toshiba CMS02
L1 1 3.6µH ±30%, 2.5A power inductor
Sumida CDRH6D26-3R6NC
R1 1 309kΩ ±1% resistor (0603)
R2 1 28.0kΩ ±1% resistor (0603)
R3, R4 2 100kΩ ±5% resistors (0603)
R5 0 N ot i nstal l ed ; shor t b y P C tr ace ( 0603)
JU1 1 2-pin header
JU2 0 Not installed, 3-pin header
U1 1 MAX8727ETB (10-pin TDFN 3mm x
3mm) (top mark AMV)
None 1 Shunts
None 1 MAX8727 EV kit PC board
Evaluates: MAX8727
MAX8727 Evaluation Kit
2 _______________________________________________________________________________________
Recommended Equipment
•2.6V to 5.5V, 5A DC power supply (VIN)
•Voltmeter
Quick Start
The MAX8727 EV kit is fully assembled and tested.
Follow these steps to verify board operation. Do not
turn on the power supply until all connections are
completed.
1) Verify that there is no shunt placed across jumper
JU1 to enable the MAX8727.
2) Connect the positive terminal of the DC power supply
to the VIN pad. Connect the negative terminal of the
DC power supply to the GND pad above the VIN pad.
3) Connect the voltmeter across the VOUT and GND
pads.
4) Turn on the 2.6V to 5.5V DC power supply and verify
that the output is 15V.
Detailed Description
The MAX8727 EV kit contains a high-efficiency, PWM
step-up DC-DC converter. The MAX8727 features a
programmable soft-start, loop compensation pin, and
an internal MOSFET switch. The EV kit operates from a
2.6V to 5.5V DC power supply, provides a regulated
15V output, and is capable of providing a 600mA load
current with a 4.5V input. The EV kit is configured for a
5V input, a 15V output, and a 1.2MHz switching fre-
quency. Operation at a different input voltage, out-
put voltage, or switching frequency may require a
different inductor, output capacitor, and compensa-
tion components. Refer to the MAX8727 data sheet for
detailed information on loop compensation and compo-
nent selection.
Jumper Selection
Shutdown Mode (
SHDN
)
The EV kit features a shutdown mode that reduces the
MAX8727 quiescent current. JU1 selects the shutdown
mode. See Table 1 for jumper JU1 functions.
Switching-Frequency Selection (FREQ)
The MAX8727 EV kit provides the option to configure
the switching frequency of the step-up DC-DC convert-
er. Table 2 lists jumper JU2 settings for configuring the
switching frequency. The EV kit is configured and
shipped to operate at 1.2MHz. For operation at 640kHz,
cut the trace between pins 1 and 2 of jumper JU2 and
short pins 2 and 3. Refer to the MAX8727 data sheet for
selecting the proper components.
Evaluating Other
Output Voltages
The EV kit is configured to provide a 15V output voltage.
However, the output voltage can be adjusted from VIN to
24V by selecting appropriate R1 and R2 values. Select
R2 in the 10kΩto 50kΩrange. R1 is then given by:
where VFB = 1.24V. For significantly different operation
points, the EV kit may require a different inductor and
component changes. Refer to the MAX8727 data sheet
for proper component selection.
RR VOUT
VFB
12 1=×
−
SHUNT
LOCATION
SHDN PIN MAX8727 OUTPUT
Installed
Connected to GND
Shutdown mode,
VOUT = VIN - VDIODE
Not installed
(default)
Connected to VIN
through R4
MAX8727 enabled,
VOUT = 15V
Table 1. Jumper JU1 Functions
SHUNT
LOCATION
FREQ PIN SWITCHING
FREQUENCY
1-2 (default)
Connected to VIN with
a PC trace 1.2MHz
2-3
Connected to GND (cut the
trace between pins 1-2
before shorting pins 2-3)
640kHz
Table 2. Jumper JU2 Functions
Evaluates: MAX8727
MAX8727 Evaluation Kit
_______________________________________________________________________________________ 3
Component Suppliers
SUPPLIER PHONE FAX WEBSITE
Murata 770-436-1300 770-436-3030 www.murata.com
Sanyo 619-661-4134 619-661-1055 www.sanyovideo.com
Sumida 847-545-6700 847-545-6720 www.sumida.com
Taiyo Yuden 408-573-4150 408-573-4159 www.t-yuden.com
Toshiba 949-455-2000 949-859-3963 www.toshiba.com/taec
Note: Indicate that you are using the MAX8727 when contacting these suppliers.
Evaluates: MAX8727
MAX8727 Evaluation Kit
4 _______________________________________________________________________________________
VIN
+4.5V TO +5.5V
GND
D1
LX1
VIN
JU2
JU1
VIN
LX2
FBIN
MAX8727
U1
FREQ
SHDN
GND2
GND1
COMP
GND
6
8
9
3
10
1
2
3
7
2
4
5
1
VOUT
15V, 600mA
L1
3.6µH
C10
100µF
6.3V
C1
OPEN
C2
10µF
6.3V
C7
4.7µF
25V
C8
4.7µF
25V
C9
4.7µF
25V
C3
1µF
C5
330pF
R5
SHORT
(PC TRACE)
C6
39pF
C4
0.033µF
R3
100kΩ
R4
100kΩ
R1
309kΩ
1%
R2
28kΩ
1%
VIN
SS
Figure 1. MAX8727 EV Kit Schematic
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
© 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
Evaluates: MAX8727
MAX8727 Evaluation Kit
Figure 2. MAX8727 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX8727 EV Kit PC Board Layout—Component Side
Figure 4. MAX8727 EV Kit PC Board Layout—Solder Side
