General Description
The MAX15039 evaluation kit (EV kit) demonstrates the
MAX15039 6A, 2MHz step-down regulator with integrated
switches for enterprise-server, telecommunication, com-
puting, and networking power-supply applications. The
EV kit is preset for a 1.8V output voltage at load currents
up to 6A from a 2.9V to 5.5V input-voltage range. A 1MHz
switching frequency and up to 95% efficiency (with the
supplied components) is achieved by the EV kit.
Features
oEvaluates Internal 26mΩRDSON High-Side and
20mΩRDSON Low-Side MOSFETs
o6A Output
o±1% Output Accuracy Over Load, Line, and
Temperature
oOperates from 2.9V to 5.5V Input Supply
oAll-Ceramic Capacitor Design
o9 Selectable Output Voltages from 0.6V to 2.5V
oProgrammable Output Voltages from 0.6V to
(0.9 x VIN) through a Resistor-Divider
o500kHz to 2MHz Adjustable Frequency
oProgrammable Soft-Start Time
oREFIN for DDR Termination and Tracking
Applications
oProven PCB Layout
oFully Assembled and Tested
Evaluates: MAX15039
MAX15039 Evaluation Kit
________________________________________________________________
Maxim Integrated Products
1
19-4712; Rev 1; 5/10
Component List
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
DESIGNATION QTY DESCRIPTION
C1, C2 2
22µF ±10%, 6.3V X5R ceramic
capacitors (0805)
TDK C2012X5R0J226K
C3, C9 2
0.1µF ±10%, 25V X7R ceramic
capacitors (0603)
TDK C1608X7R1E104K
C4, C6 2
0.01µF ±10%, 50V X7R ceramic
capacitors (0603)
TDK C1608X7R1H103K
C5 1
2.2µF ±10%, 16V X5R ceramic
capacitor (0603)
Murata GRM188R61C225K
C7 0 Not installed, ceramic capacitor
(0603)
C8 1
0.022µF ±10%, 50V X7R ceramic
capacitor (0603)
TDK C1608X7R1H223K
C10 1
560pF ±10%, 50V X7R ceramic
capacitor (0603)
TDK C1608X7R1H561K
C11 1
1500pF ±10%, 50V X7R ceramic
capacitor (0603)
TDK C1608X7R1H152K
C12 1
33pF ±5%, 50V C0G ceramic
capacitor (0603)
TDK C1608C0G1H330CT
DESIGNATION QTY DESCRIPTION
C13, C14 0 N ot i nstal l ed , cer am i c cap aci tor s ( 0805)
C15 1
1000pF ±10%, 50V X7R ceramic
capacitor (0603)
TDK C1608X7R1H102K
IN, OUT, PGND 3 N oni nsul ated b anana j ack connector s
JU1, JU2 2 2-pin headers
JU3, JU4, JU5 3 3-pin headers
L1 1
0.47µH, 8.3mΩ, 9.0A inductor
(7.7mm x 7mm)
TOKO FDV0620-R47
R1 1 2.2Ω ±5% resistor (0603)
R2 1 10kΩ ±5% resistor (0603)
R3 1 1kΩ ±5% resistor (0603)
R4 1 2.67kΩ ±1% resistor (0603)
R5 1 20kΩ ±5% resistor (0603)
R6 1 158Ω ±1% resistor (0603)
R7 1 49.9kΩ ±1% resistor (0603)
R8, R9 0 Not installed, resistors (0603)
U1 1 2MHz buck controller (24 TQFN-EP*)
Maxim MAX15039ETG+
— 5 Shunts (JU1–JU5)
— 1 PCB: MAX15039 EVALUATION KIT+
PART TYPE
MAX15039EVKIT+ EV Kit
+
Denotes lead(Pb)-free and RoHS compliant.
*
EP = Exposed pad.
Evaluates: MAX15039
Quick Start
Required Equipment
• MAX15039 EV kit
• 2.9V to 5.5V, 6A DC power supply
• One digital multimeter (DMM)
• One load up to 6A
Procedure
The MAX15039 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 competed.
1) Preset the DC power supply to 5V and disable the
power-supply output.
2) Set the load to 6A or less and disable the load.
3) Verify that shunts are installed on the EV kit jumpers
as follows:
JU1: Installed (MAX15039 disabled)
JU2: Installed (internal 0.6V reference)
VOUT = 1.8V:
JU3: Not installed
JU4: Pins 1-2
JU5: Pins 2-3 (forced-PWM mode)
4) Connect the power-supply positive terminal to the
IN banana jack and the negative terminal to the
PGND banana jack.
5) Connect the load positive terminal to the OUT
banana jack and the negative terminal to the
PGND banana jack.
6) Set the DMM to measure voltage. Connect the
positive terminal to the OUT PCB pad and the neg-
ative terminal to the PGND PCB pad.
7) Enable the power supply.
8) Enable the load.
9) Remove the shunt from jumper JU1 (MAX15039
enabled).
10) Verify that the DMM measures 1.8V.
Detailed Description of Hardware
The MAX15039 EV kit demonstrates the MAX15039 6A,
2MHz step-down regulator with integrated switches in a
24-pin TQFN surface-mount package with an exposed
pad. Applications include enterprise-server, telecom-
munication, computing, and networking power supplies.
The EV kit generates selectable output voltages from
0.6V to 2.5V at load currents up to 6A. The output volt-
age should be configured only BEFORE power-up using
jumpers JU3 (CTL1) and JU4 (CTL2). Once the IC is
enabled using jumper JU1 (EN), jumpers JU3 and JU4
should not be changed until power cycling or disabling
the IC. The EV kit can also program the output voltage
from 0.6V to (0.9 x VIN) through resistor-dividers R8 and
R9. Jumper JU2 (REFIN) configures the EV kit reference
voltage as an internal 0.6V reference or a user-supplied
0V to (VDD - 2V) voltage reference connected across
the REF_IN and GND PCB pads.
The EV kit operates in three different functional modes
(forced PWM, monotonic startup, and skip), as config-
ured by jumper JU5 (MODE). The EV kit shows a 1MHz
switching frequency and up to 95% efficiency with the
supplied components. The EV kit can evaluate other
switching frequencies between 500kHz and 2MHz. See
the
Evaluating Other Switching Frequencies (FREQ)
section for more information. The EV kit also provides a
PWRGD PCB pad to access the IC’s power-good logic
output. The EV kit operates from a 2.9V to 5.5V input
DC power supply connected across the IN and PGND
banana jacks.
Regulator Enable (EN)
The MAX15039 features a shutdown mode to minimize the
IC quiescent current. To shut down the IC, install a shunt
on jumper JU1. For normal operation, remove the shunt
from JU1. See Table 1 to configure jumper JU1.
MAX15039 Evaluation Kit
2 _______________________________________________________________________________________
Component Suppliers
SUPPLIER PHONE WEBSITE
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
TDK Corp. 847-803-6100 www.component.tdk.com
TOKO America, Inc. 847-297-0070 www.tokoam.com
Note: Indicate that you are using the MAX15039 when contacting these component suppliers.
Reference Voltage (REFIN)
The MAX15039 uses an internal 0.6V reference or an
external reference input. To use the internal 0.6V refer-
ence, install a shunt on jumper JU2 shorting U1’s REFIN
and SS pins.
When using an external reference, perform the follow-
ing steps:
1) Remove the shunt from jumper JU2.
2) Install a surface-mount 0603 capacitor at C7 for
soft-starting, if needed.
3) Connect a 0V to (VDD - 2V) reference across the
REF_IN and GND PCB pads.
The IC regulates FB to the voltage at U1’s REFIN pin.
The internal soft-start is not available when using an
external reference. Refer to the
Soft-Start and REFIN
section in the MAX15039 IC data sheet for more infor-
mation on using the REFIN features. See Table 2 to
configure jumper JU2.
Evaluating Other Output Voltages
The EV kit comes preset to a 1.8V output voltage. The
output voltage is selectable using jumpers JU3 (CTL1)
and JU4 (CTL2) to provide three logic level inputs:
VDD, unconnected, and GND. The logic states of
CTL1 and CTL2 should be selected only before
power-up. CTL1 and CTL2 should not be changed
once soft-start is complete. If the output voltage needs to
be reselected, perform the following steps:
1) Disable the regulator using jumper JU1, or remove
power.
2) Set the CTL1 and CTL2 logic states using jumpers
JU3 and JU4.
3) Enable the regulator, or apply power.
See Table 3 to configure jumpers JU3 and JU4.
When externally programming the MAX15039, install a
8.06kΩsurface-mount 0603 resistor at R8 and then
select a value for a surface-mount 0603 resistor at R9
using the following equation:
where VOUT is the desired output voltage and VREFIN is
the voltage applied at the REF_IN and GND PCB pads.
Refer to the MAX15039 IC data sheet for information on
selecting output inductor, capacitor, and compensation
components to optimize the circuit for different output
voltages.
Mode Selection
The MAX15039 IC’s three functional modes (forced
PWM, monotonic startup, and skip) are programmable
using jumper JU5. Refer to the
MODE Selection
section
in the MAX15039 IC data sheet for more information on
the IC’s three functional modes. See Table 4 to config-
ure jumper JU5.
R9 806
kVk
VV if u
REFIN
OUT REFIN
ΩΩ
[]
=×
()
−
()
.,ssing external VREFIN
R0.6V or9806
06
kk
VV
OUT
ΩΩ
[]
=×
()
−
()
.
.
Evaluates: MAX15039
MAX15039 Evaluation Kit
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Table 1. Regulator Enable (JU1)
SHUNT
POSITION
EN PIN
CONNECTION
MAX15039
FUNCTION
Not installed Pulled up to IN through
resistor R2 Enabled
Installed GND Disabled
Table 2. Reference Voltage (JU2)
SHUNT
POSITION
REFIN PIN
CONNECTION
REFERENCE
VOLTAGE
Installed U1 SS pin Internal 0.6V reference
Not installed REF_IN PCB pad
through resistor R3
User-supplied reference
voltage
Range: 0V to (VDD - 2V)
Evaluates: MAX15039
Evaluating Other Switching
Frequencies (FREQ)
The EV kit comes preset at a 1MHz switching frequen-
cy. To evaluate other frequencies, select a different
value for surface-mount 0603 resistor R7 using the fol-
lowing equation:
where fSis the desired switching frequency in mega-
hertz and must be between 500kHz and 2MHz. Refer to
the MAX15039 IC data sheet for information on select-
ing output inductor, capacitor, and compensation com-
ponents to optimize the circuit for different switching
frequencies.
Power Good (PWRGD)
The MAX15039 PWRGD is an open-drain output that
goes to high impedance when VFB is above 0.925 x
VREFIN and VREFIN is above 0.54V for at least 48 clock
cycles. PWRGD pulls low when VFB is below 90% of
VREFIN or VREFIN is below 0.54V for at least 48 clock
cycles. PWRGD is also low during shutdown. On the EV
kit, the PWRGD PCB pad is pulled up to VDD through
resistor R5. Use the GND PCB pad as a ground refe-
rence for this signal.
Rss7 49 9
095
1005kk
fMHz
S
ΩΩ
[]
=×
[]
⎛
⎝
⎜⎞
⎠
⎟
−
.
..
µµ
MAX15039 Evaluation Kit
4 _______________________________________________________________________________________
Table 4. Mode Selection (JU5)
SHUNT
POSITION
MODE PIN
CONNECTION
MAX15039 IC
FUNCTIONAL MODE
2-3 GND Forced PWM
Not installed Unconnected
Forced PWM, monotonic
startup into prebiased
output
1-2 VDD Skip, monotonic startup
into prebiased output
SHUNT
POSITION
(JU3)
CTL1 PIN
CONNECTION
SHUNT
POSITION
(JU4)
CTL2 PIN
CONNECTION VOUT (V) VOUT (V) WHEN USING
EXTERNAL VREFIN
2-3 GND 2-3 GND 0.6V* or 0.6V < VOUT ≤
0.9 x VIN**
VREFIN* or VREFIN <
VOUT ≤ 0.9 x VIN**
1-2 VDD 1-2 VDD 0.7 VREFIN x (7/6)
2-3 GND Not installed Unconnected 0.8 VREFIN x (4/3)
2-3 GND 1-2 VDD 1.0 VREFIN x (5/3)
Not installed Unconnected 2-3 GND 1.2 VREFIN x 2
Not installed Unconnected Not installed Unconnected 1.5 VREFIN x 2.5
Not installed Unconnected 1-2 VDD 1.8 VREFIN x 3
1-2 VDD 2-3 GND 2.0 VREFIN x (10/3)
1-2 VDD Not installed Unconnected 2.5 VREFIN x (25/6)
*
Install a surface-mount 0603 8.06kΩresistor at R8 and do not install a resistor at R9.
**
Install a surface-mount 0603 8.06kΩresistor at R8 and a resistor at R9 (see the equation in the
Evaluating Other Output Voltages
section).
Table 3. Output-Voltage Selection (JU3, JU4)
Evaluates: MAX15039
MAX15039 Evaluation Kit
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Figure 1. MAX15039 EV Kit Schematic (Application Circuit)
Evaluates: MAX15039
MAX15039 Evaluation Kit
6 _______________________________________________________________________________________
Figure 2. MAX15039 EV Kit Component Placement Guide—Component Side
Evaluates: MAX15039
MAX15039 Evaluation Kit
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Figure 3. MAX15039 EV Kit PCB Layout—Component Side
Evaluates: MAX15039
MAX15039 Evaluation Kit
8 _______________________________________________________________________________________
Figure 4. MAX15039 EV Kit PCB Layout—Layer 2
Evaluates: MAX15039
MAX15039 Evaluation Kit
_______________________________________________________________________________________ 9
Figure 5. MAX15039 EV Kit PCB Layout—Layer 3
Figure 6. MAX15039 EV Kit PCB Layout—Solder Side
Evaluates: MAX15039
MAX15039 Evaluation Kit
10 ______________________________________________________________________________________
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 ____________________
11
© 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Evaluates: /MAX15039
MAX15039 Evaluation Kit
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 7/09 Initial release —
1 5/10 Updated the Detailed Description of Hardware, Reference Voltage (REFIN),
and Evaluating Other Output Voltages sections and Table 3 2, 3, 4
