Evaluates: MAX15020
MAX15020 Evaluation Kit
General Description
The MAX15020 evaluation kit (EV kit) is a fully assembled
and tested PCB that evaluates the MAX15020 PWM step-
down regulator IC with an integrated high-side switch.
The MAX15020 is equipped with a reference input for the
feedback error amplier, allowing dynamic output-voltage
programming. The MAX15020 EV kit operates over a wide
input-voltage range of 7.5V to 40V and provides up to 2A.
The MAX15020 internal switching frequency can be
set to either 300kHz or 500kHz. The MAX15020 EV kit
features a SYNC input to provide external frequency
synchronization for sensitive applications. The EV kit uses
a MAX15020 step-down regulator in a 20-pin thin QFN
package. The MAX15020 IC operates over the automotive
temperature range of -40°C to +125°C and is suitable for
printers and industrial applications.
Features
●Wide 7.5V to 40V Input Range
●Dynamic Output-Voltage Control from 0.8V to 36V
with 2A Load
●Selectable 300kHz/500kHz Switching Frequency
●Turn-On/Off Control
●Demonstrates MAX15020 IC Low Shutdown Current
●High Efficiency Up to 96% (VIN = 36V, VOUT = 30V,
ILOAD = 2A)
●Demonstrates MAX15020 IC Overcurrent and
Thermal Protection
● Space-Saving 5mm x 5mm, 20-pin TQFN Package
●Fully Assembled and Tested
Quick Start
Recommended Equipment
Before beginning, the following equipment is needed:
• 7.5V to 40V adjustable, 3A power supply
• 15Ω resistive load rated for 75W or greater
• Two digital voltmeters
Procedure
The MAX15020 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) Verify that a shunt is not installed at jumper JU1
(default 32V turn-on voltage).
2) Verify that shunts are installed on pins 1-2 of jumpers
JU2 (REFIN = REFOUT) and JU3 (300kHz switching
frequency).
3) Connect the resistive load between the OUT PCB pad
and the PGND PCB pad.
4)
Connect digital voltmeters across the IN and PGND
pads, and the OUT and PGND pads on the EV kit board.
5) Connect the power supply’s positive terminal to the IN
PCB pad on the EV kit, and connect the power-supply
ground terminal to the PGND PCB pad.
6) Turn on the power supply.
7) Set the power-supply voltage to 36V.
8) Verify that the voltmeter at OUT measures 30V.
19-0804; Rev 3; 5/15
+Denotes lead(Pb)-free and RoHS compliant.
PART TYPE
MAX15020EVKIT+ EV Kit
Ordering Information
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Evaluates: MAX15020
MAX15020 Evaluation Kit
Detailed Description of Hardware
The MAX15020 EV kit circuit uses a MAX15020 step-
down regulator IC (U1) to implement a step-down DC-DC
regulator circuit. The EV kit operates over a 7.5V to
40V input range. The circuit provides a dynamically
programmable output range of 0.8V to 36V and can
deliver up to 2A of current with excellent line and load
regulation. The MAX15020 step-down regulator features an
internal high-side-low RDS(ON) MOSFET to achieve higher
efficiency and lower overall system cost. The MAX15020
also features configurable soft-start, shutdown control,
cycle-by-cycle current limit, hiccup-mode output short-
circuit protection, and thermal shutdown. The undervoltage
lockout (UVLO) threshold is configurable by choosing the
appropriate R1 and R2 resistors.
The MAX15020 EV kit features a selectable 300kHz
or 500kHz switching-frequency operation, in addition
to a SYNC input that can be used to synchronize the
MAX15020 to frequencies operating in the 300kHz to
500kHz range. An external reference input (REFIN_EXT)
is available to dynamically change the output voltage.
Jumper Selection
ON/OFF Mode
The MAX15020 EV kit features a ON/OFF mode that
reduces the MAX15020 supply current to 6μA (typ).
The 3-pin jumper JU1 selects the ON/OFF mode for
the MAX15020 EV kit. See Table 1 for jumper JU1
configurations
REFIN_EXT Input
The MAX15020 features a reference input for the internal
error amplifier. The voltage applied to REFIN_EXT PCB
pad is used to dynamically change the circuit’s output volt-
age. Jumper JU2 connects REFIN to REFOUT to use the
MAX15020’s 1V internal reference voltage. See Table 2 for
jumper JU2 configurations. To change the MAX15020 EV
kit output voltage using REFIN_EXT, refer to the Setting
the Output Voltage section in the MAX15020 IC data sheet.
Frequency Selection
Jumper JU3 selects the MAX15020 operating switching
frequency between 300kHz or 500kHz. See Table 3 for
switching frequency selection.
Conguring the Output Voltage (OUT)
The MAX15020 EV kit step-down regulator output
voltage is configured to 30V by resistors R7 and R8,
and with REFIN = REFOUT. The EV kit’s output voltage
(OUT) can be reconfigured in the range of 0.8V to 36V by
replacing resistors R7 and R8. To select a new value for
resistor R8, refer to the Compensation Design section in
the MAX15020 IC data sheet. Use the following equation
to reconfigure the output voltage to the desired value:
OUT
REFIN
R7
R8 V1
V
=
−
where V
OUT
is the desired output voltage in volts, V
REFIN
is the voltage supplied by REFOUT or REFIN_EXT, and R7
is typically 10kΩ.
The MAX15020 output voltage can also be adjusted
dynamically by driving REFIN_EXT between 0 and 3.6V.
To use the REFIN_EXT input, place a shunt across pins
2-3 of jumper JU2.
*Default position.
*Default position.
*Default position. When operating the MAX15020 with an exter-
nal clock signal at SYNC, place the shunt on pins 1-2. Refer to
the Oscillator/Sychronization Input section of the MAX15020 IC
data sheet for more information.
Table 1. Jumper JU1 ON/OFF Mode Table 3. Jumper JU3 Frequency Selection
Table 2. Jumper JU2 Reference-Voltage
Input
SHUNT
LOCATION ON/OFF PIN MAX15020 OUTPUT
1-2 Connects to VIN directly MAX15020 enabled
2-3 Connects to GND MAX15020 disabled
None* Connects to VIN through
R1 and R2 resistors
MAX15020 enabled at
VIN @ 32V
SHUNT
LOCATION FSEL PIN MAX15020 SWITCHING
FREQUENCY
1-2* Connects to VREG 300kHz
2-3 Connects to GND 500kHz
SHUNT
LOCATION REFIN PIN VOUT
1-2* Connects directly to
REFOUT 30V
2-3 Externally controlled by
REFIN_EXT voltage
Dependent on voltage
at REFIN_EXT
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Evaluates: MAX15020
MAX15020 Evaluation Kit
Reconfiguring the MAX15020 EV kit for a new output
voltage may require replacing inductor L1 and capacitors
C1 and/or C6. To select a new value for inductor L1 and
capacitors C1 and C6, refer to the Inductor Selection,
Output Capacitor Selection, and Input Capacitor Selection
sections, respectively, in the MAX15020 IC data sheet.
Conguring the ON/OFF Threshold
The MAX15020 EV kit turn-on threshold is configured to
32V with resistors R1 and R2. The MAX15020 turns on
when the input voltage (V
IN
) is approximately above 32V
and ON/OFF is ≥ 1.23V. The ON/OFF threshold can be
reconfigured to a desired value by appropriately selecting
resistors R1 and R2. Refer to the Setting the ON/OFF
Threshold section in the MAX15020 IC data sheet. To
reconfigure the UVLO threshold, use the following equation:
UVLO
V
R1 R2 1
1.23
=×−
where resistor R1 should be in the range of 100kΩ and
V
UVLO
is the desired UVLO threshold in volts.
Place a shunt across pins 1-2 of jumper JU1 for always-on
operation, which bypasses the on/off threshold. Resistor R11
is utilized to prevent excessive power dissipation in resistor
R2 when the shunt at jumper JU1 is installed on pins 1-2.
Synchronization Input (SYNC)
The MAX15020 EV kit circuit features a selectable
300kHz or 500kHz switching frequency. Jumper JU3 sets
the internal switching frequency. The EV kit’s SYNC PCB
pad can be used to synchronize the MAX15020 with an
external digital clock in the range of 300kHz to 500kHz.
When SYNC is driven with an external digital clock, the
MAX15020 synchronizes to the rising edge of the external
clock.
The digital square-wave clock source must provide the
following signal qualities:
• Output voltage: Logic-low = 0 to 0.8V, logic-high =
2V to 5.5V
• Input frequency = 300kHz to 500kHz (refer to the
MAX15020 IC data sheet for more information on the
SYNC input)
• Minimum pulse width = 200ns
To use external synchronization, connect the external
square-wave clock to the SYNC and GND pads.
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Evaluates: MAX15020
MAX15020 Evaluation Kit
Note: Indicate that you are using the MAX15020 when contact-
ing these component suppliers.
DESIGNATION QTY DESCRIPTION
C1, C6 2
560µF ±20%, 50V low ESR
electrolytic capacitors
(12.5mm x 25mm)
SANYO 50ME560WX
C2, C4,
C10 3
1µF ±10%, 25V X7R ceramic
capacitors (0805)
TDK C2012X7R1E105K
C3, C5,
C7, C9 4
0.1µF ±10%, 50V X7R ceramic
capacitors (0603)
TDK C1608X7R1H104K
C8 1
0.22µF ±10%, 50V X7R ceramic
capacitor (0805)
Murata GRM21BR71H224K
C11 1
0.027µF ±10%, 50V X7R ceramic
capacitor (0603)
AVX 06035C273KAT2A
C12 1
0.1µF ±10%, 50V X7R ceramic
capacitor (0805)
TDK C2012X7R1H104K
C13 1
330pF ±5%, 50V C0G ceramic
capacitor (0603)
TDK C1608C0G1H331J
D1 1 60V, 3A Schottky diode (SMA)
Diodes Inc. B360A
DESIGNATION QTY DESCRIPTION
D2 1 100V, 150mA Schottky diode
(SOD-123) Vishay BAT46W
JU1–JU3 3 3-pin headers
L1 1 22µH, 4.7A inductor
Sumida CDRH127/LDNP-220MC
R1 1 97.6kΩ ±1% resistor (0603)
R2 1 4.02kΩ ±1% resistor (0603)
R3, R4 210kΩ ±5% resistors (0603)
R5 1 10Ω ±5% resistor (0603)
R6, R7 210kΩ ±1% resistors (0603)
R8 1 340Ω ±1% resistor (0603)
R9 1 15.8kΩ ±1% resistor (0603)
R10 1 0Ω ±5% resistor (0603)
R11 120kΩ ±1% resistor (0603)
TP1–TP4 4 PC mini red test points
U1 1
PWM step-down regulator (20
TQFN) (5mm x 5mm x 0.8mm)
Maxim MAX15020ATP+
— 3 Shunts (JU1–JU3)
— 1 PCB: MAX15020 EVALUATION
KIT+
SUPPLIER PHONE WEBSITE
AVX Corp. 843-448-9411 www.avxcorp.com
Diodes Inc. 805-446-4800 www.diodes.com
Murata Americas 770-436-1300 www.murataamericas.com
SANYO 619-661-6835 www.sanyodevice.com
Sumida Corp. 847-545-6700 www.sumida.com
TDK Corp. 847-803-6100 www.component.tdk.com
Vishay 203-268-6261 www.vishay.com
Component List
Component Suppliers
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Evaluates: MAX15020
MAX15020 Evaluation Kit
Figure 1. MAX15020 EV Kit Schematic
MAX15020
U1
L1
22µH
TP4
TP3
D1
D2
15
1617181920
1
1
14
13
12
11
LX
VIN
VIN
VIN
GND VREG
COMP
LX
LX
BST
N.C.
FB
R7
10kΩ
1%
R9
15.8kΩ
1%
R6
10kΩ
1%
R10
0Ω
R8
340Ω
1%
C11
0.027µF
C4
1µF
C3
0.1µF
50V
C1
560µF
50V
R11
20kΩ
1%
R1
97.6kΩ
1%
R2
4.02kΩ
1% C5
0.1µF
50V
C9
0.1µF
50V
C8
0.22µF
R3
10kΩ
R4
10kΩ
C10
1µF
R5
10Ω
C2
1µF
VREG
COMP
2
2
FB
3
3
1
1
2
2
3
3
ON/OFF
4REFOUT
REFIN
5
6
FSEL SYNC PGNDNDVREG
VREG
7 8 9 10
CSS
FB
REFOUT
JU2
JU3
JU1
REFOUT
TP1
TP2
SYNC
IN
PGND
GND
REFIN_EXT
ON/OFF
C12
0.1µF
C13
330pF
PGND
OUT
C7
0.1µF
50V
C6
560µF
50V
COMP
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Evaluates: MAX15020
MAX15020 Evaluation Kit
Figure 2. MAX15020 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX15020 EV Kit PCB Layout—Component Side
Figure 4. MAX15020 EV Kit PCB Layout—GND Layer 2
1.0” 1.0”
1.0”
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 specications without notice at any time.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2015 Maxim Integrated Products, Inc.
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Evaluates: MAX15020
MAX15020 Evaluation Kit
REVISION
NUMBER
REVISION
DATE REVISION DESCRIPTION PAGES
CHANGED
0 4/07 Initial release —
1 11/07 Updated Ordering Information table format; corrections to Procedures (step 2),
Conguring ON/OFF Threshold, and Figure 1. 1–4
2 6/08 Changed part number for C13 in Component List. 1
3 5/15 Deleted automotive reference in General Description section; moved Quick Start
section to page 1 and Component List and Component Suppliers tables to page 4 1, 4
Revision History
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
