Datasheet

Evaluates: MAX15020
MAX15020 Evaluation Kit
2 _______________________________________________________________________________________
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 these steps to verify board operation. Caution:
Do not turn on the power supply until all connec-
tions 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.
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 pro-
grammable output range of 0.8V to 36V and can deliver
up to 2A of current with excellent line and load regula-
tion. The MAX15020 step-down regulator features an
internal high-side-low R
DS(ON)
MOSFET to achieve high-
er efficiency and lower overall system cost. The
MAX15020 also features configurable soft-start, shut-
down control, cycle-by-cycle current limit, hiccup-mode
output short-circuit protection, and thermal shutdown.
The undervoltage lockout (UVLO) threshold is config-
urable 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 inter-
nal error amplifier. The voltage applied to REFIN_EXT
PCB pad is used to dynamically change the circuit’s
output voltage. 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 sec-
tion in the MAX15020 IC data sheet.
Component Suppliers
SUPPLIER PHONE WEBSITE
AVX Corp. 843-448-9411 www.avxcorp.com
Diodes Inc. 805-446-4800 www.diodes.com
Murata 770-436-1300 www.murata.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
Note: Indicate that you are using the MAX15020 when contacting
these component suppliers.
Table 1. Jumper JU1 ON/
OOFFFF
Mode
SHUNT
LOCATION
ON/OFF PIN
MAX15020 OUTPUT
1-2
Connects to V
IN
directly
MAX15020 enabled
2-3 Connects to GND MAX15020 disabled
None*
C onnects to V
I N
thr oug h
R1 and R2 r esi stor s
MAX15020 enabled at
V
IN
≅ 32V
* Default position.
Table 2. Jumper JU2 Reference-Voltage
Input
SHUNT
LOCATION
REFIN PIN V
OUT
1-2*
Connects directly to
REFOUT
30V
2-3
Externally controlled by
REFIN_EXT voltage
Dependent on voltage
at REFIN_EXT
* Default position.