19-4101; Rev 0; 5/08
MAX15022 Evaluation Kit
General Description
The MAX15022 evaluation kit (EV kit) circuit demon-
strates the MAX15022 IC, which integrates two high-
performance PWM switching step-down regulators and
two low-dropout (LDO) controllers. Each controller and
regulator features independent enable controls for
power-up sequence operation. The EV kit is designed
to operate from a single 4.5V to 5.5V DC power supply.
The synchronous step-down outputs provide 3.3V/4A
and 1.5V/2A, and can be configured for power-up
sequencing or tracking operation. The converter
switching frequency is set to 2MHz and operates 180°
out-of-phase, reducing input voltage ripple and total
RMS input ripple current. The LDO outputs provide
2.5V and 1.2V, at up to 500mA each. Each LDO con-
troller is powered from either the input power source or
one of the regulator outputs.
o
4.5V to 5.5V Input Range
o
Regulator Outputs
3.3V at 4A
1.5V at 2A
o
2MHz Switching Frequency
o
LDO Outputs
2.5V (Up to 500mA)
1.2V (Up to 500mA)
o
Independent Enable Inputs for All Outputs
o
Configurable Power-Up Sequencing for Outputs
o
Configurable Power-Up Tracking for Regulators
(VOUT1, VOUT2)
o
Thermal Shutdown and Hiccup-Mode Short-
Circuit Protection
o
Fully Assembled and Tested
Features
Evaluates: MAX15022
Ordering Information
PART
MAX15022EVKIT+
TYPE
EV Kit
+Denotes
lead-free and RoHS-compliant.
Component List
DESIGNATION
QTY
DESCRIPTION
150µF ±20%, 10V aluminum
electrolytic capacitor
(6.6mm x 6.6mm)
Panasonic EEEFK1A151P
0.1µF ±10%, 16V X7R ceramic
capacitors (0603)
Murata GRM188R71C104K
10µF ±10%, 6.3V X7R ceramic
capacitors (0805)
Murata GRM21BR70J106K
180pF ±5%, 50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H181J
390pF ±5%, 50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H391J
10pF ±5%, 50V C0G ceramic
capacitors (0603)
Murata GRM1885C1H100J
Not installed, capacitors (0805)
DESIGNATION
C15
QTY
1
DESCRIPTION
68pF ±5%, 50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H680J
270pF ±5%, 50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H271J
1µF ±10%, 10V X7R ceramic
capacitors (0805)
TDK C2012X7R1A105K
Not installed, ceramic capacitors
(0603)
2200pF ±10%, 16V X7R ceramic
capacitors (0603)
Murata GRM188R71C222K
3-pin headers
0.47µH, 5A inductor
Vishay IHLP-1616BZ-ER-R47-M-01
1µH, 4A inductor
Vishay IHLP-1616BZ-ER-1R0-M-01
C1
1
C2, C4, C9,
C10, C14, C18
C3, C8, C11,
C12, C19, C21
C17
1
6
C20, C22
2
6
C25, C26
0
C5
1
C27, C28
JU1–JU4
L1
L2
2
4
1
1
C6
1
C7, C16
C13, C23, C24
2
0
________________________________________________________________
Maxim Integrated Products
1
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.
MAX15022 Evaluation Kit
Evaluates: MAX15022
Component List (continued)
DESIGNATION
Q1, Q2
R1, R7
R2
R3
R4
R5
R6, R9, R10
R11
R12
R13
R14, R18
R15, R19, R24
QTY
2
2
1
1
1
1
3
1
1
1
2
3
DESCRIPTION
-20V, 1.5A pnp transistors
(SOT223-4)
Fairchild Semiconductor BCP69
120Ω ±5% resistors (0603)
100Ω ±1% resistor (0603)
23.7kΩ ±1% resistor (0603)
7.5kΩ ±1% resistor (0603)
15.8kΩ ±1% resistor (0603)
11.5kΩ ±1% resistors (0603)
1.5kΩ ±1% resistor (0603)
18.7kΩ ±1% resistor (0603)
15Ω ±1% resistor (0603)
24.9kΩ ±1% resistors (0603)
16.5kΩ ±1% resistors (0603)
—
—
4
1
U1
1
DESIGNATION
R16
R17, R21
R20
R22
R23
R25
R26
R27, R28
QTY
1
2
1
1
1
1
1
0
DESCRIPTION
1kΩ ±1% resistor (0603)
15kΩ ±1% resistors (0603)
2.55kΩ ±1% resistor (0603)
47.5kΩ ±1% resistor (0603)
10.5kΩ ±1% resistor (0603)
18.2kΩ ±1% resistor (0603)
10kΩ ±1% resistor (0603)
Not installed, resistors (1206)
Dual regulator/LDO controller
(28 TQFN-EP*)
Maxim MAX15022ATI+
Shunts (JU1–JU4)
PCB: MAX15022 Evaluation Kit+
*EP
= Exposed pad.
Component Suppliers
SUPPLIER
Fairchild Semiconductor
Murata Electronics North America, Inc.
Panasonic Corp.
TDK Corp.
Vishay
PHONE
888-522-5372
770-436-1300
714-373-7366
847-803-6100
203-268-6261
WEBSITE
www.fairchildsemi.com
www.murata-northamerica.com
www.panasonic.com
www.component.tdk.com
www.vishay.com
Note:
Indicate that you are using the MAX15022 when contacting these component suppliers.
Quick Start
Required Equipment
Before beginning, the following equipment is needed:
• Adjustable 4.5V to 5.5V, 5A DC power supply
• Four voltmeters
2) Install shunts across pins 1-2 of jumpers JU3
(VOUT2 sequences after VOUT1) and JU4
(sequencing mode for outputs VOUT1, VOUT2).
3) Connect the voltmeter positive-terminal inputs to the
VOUT1–VOUT4 PCB pads.
4) Connect the voltmeter negative-terminal inputs to
the respective output’s PGND PCB pads.
5) Connect a DC power supply to the VIN and PGND
pads and set the voltage to 5V.
6) Enable the power-supply output.
7) Verify that the voltmeters at VOUT1–VOUT4 mea-
sure 3.3V, 1.5V, 2.5V, and 1.2V, respectively.
Procedure
The MAX15022 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) Install shunts across pins 2-3 of jumpers JU1
(VOUT1 input source for VOUT3) and JU2 (VOUT2
input source for VOUT4).
2
_______________________________________________________________________________________
MAX15022 Evaluation Kit
Detailed Description of Hardware
The MAX15022 EV kit circuit demonstrates the
MAX15022 IC, which integrates two high-performance
PWM switching synchronous step-down regulators and
two LDO controllers. The EV kit regulator outputs can
be configured for sequencing, ratiometric-tracking, or
coincident-tracking mode. The MAX15022 IC operates
with either step-down regulator outputs as the master;
however, the EV kit is designed with VOUT1 as the
master during tracking operation. Each controller and
regulator features independent enable controls for
power-up sequencing operation. The EV kit is designed
to operate from a single DC power supply that provides
4.5V to 5.5V and 5A of current.
The EV kit’s dual step-down regulator’s outputs (VOUT1
and VOUT2) are configured for 3.3V and 1.5V, providing
up to 4A and 2A, respectively. The regulator’s tracking
sequencing operation modes are selectable through
jumpers JU3 and JU4. The switching frequency is set to
2MHz by resistor R24 and can be programmed from
500kHz to 4MHz. The outputs operate 180° out-of-
phase to reduce input voltage ripple and total RMS
input ripple current.
The LDO outputs (VOUT3 and VOUT4) are configured
for 2.5V and 1.2V, respectively, and provide up to
500mA each. Jumpers JU1 and JU2 select the LDO’s
input power source or configure VOUT3 and VOUT4 for
power-supply sequencing to the regulator outputs,
VOUT1 and VOUT2, respectively.
The MAX15022 IC operates with either regulator output
as the master or slave during tracking mode. However,
the MAX15022 EV kit is designed with VOUT1 as the
master and VOUT2 as the slave during tracking opera-
tion. See Table 1 for jumpers JU3 and JU4 configura-
tion for operating the EV kit step-down regulators in
tracking or sequencing mode.
Evaluates: MAX15022
Table 1. VOUT1/VOUT2 Tracking/
Sequencing Operation (JU3, JU4)
SHUNT
POSITION
JU3
1-2
2-3
JU4
1-2
2-3
—
—
Sequence mode
Coincident-tracking mode
(VOUT1 master, VOUT2
slave)
Ratiometric-tracking
mode (VOUT1 master,
VOUT2 slave)
EV KIT CIRCUIT
MODIFICATION
EV KIT VOUT1/VOUT2
OPERATION
2-3
2-3
Resistor R14 must
be removed
Input Power Source
The MAX15022 EV kit regulator outputs (VOUT1 and
VOUT2) are optimized to provide up to 4A and 2A,
respectively, when operating with an input-voltage
source of 4.5V to 5.5V. The EV kit accommodates input
voltages down to 2.35V; however, each output rail’s
passive filtering, enabling, and compensation circuitry
needs to be revisited to confirm optimal performance.
Additionally, VOUT1’s 3.3V rail likely needs to be read-
justed to a lower-than-VIN potential. Refer to the
MAX15022 IC data sheet for additional information on
the minimum voltage requirements, as well as the
PWM
Controllers Design Procedure
and
LDO Controllers
Design Procedure
sections.
Regulator's Power Tracking/Sequencing
The MAX15022 EV kit can be configured to power up
and power down the VOUT1 and VOUT2 outputs in
sequencing, ratiometric-tracking, or coincident-
tracking mode by configuring jumpers JU3 and JU4.
The EV kit’s VOUT1 and VOUT2 outputs are configured
for coincident-tracking operation by default. VOUT2
output voltage ramps up, tracking the VOUT1 voltage
using resistor pairs R14/R15 and R18/R19, which sets
the resistor-divider ratios. Place shunts across pins 2-3
of jumpers JU3 and JU4 to operate VOUT1 and VOUT2
in coincident tracking mode.
In ratiometric-tracking mode, VOUT1 and VOUT2 soft-
start controllers are synchonized, and hence, their
respective output voltages track ratiometrically. For
ratiometric-tracking operation, the EV kit PCB requires a
minor modification. Place shunts across pins 2-3 of
jumpers JU3 and JU4 and remove resistor R14 for ratio-
metric-tracking mode.
When operating the EV kit in sequencing mode, each
regulator operates independently with its own enable
input. To operate regulator outputs VOUT1 and VOUT2
in sequencing mode, install shunts across pins 1-2 of
jumpers JU3 and JU4. The VOUT2 output does not turn
on until VOUT1 rises above the EN2 1.22V threshold.
Refer to the
Tracking/Sequencing
section in the
MAX15022 IC data sheet for additional information on
operating in coincident/ratiometric-tracking and
sequencing modes, and to calculate the proper values
for resistor pairs R14/R15 and R18/R19.
_______________________________________________________________________________________
3
MAX15022 Evaluation Kit
Evaluates: MAX15022
Step-Down Regulator Output Voltages
(VOUT1, VOUT2)
Regulator output VOUT1 is set to 3.3V with resistors
R22 and R23 and provides up to 4A at 90% efficiency.
Capacitors C15, C16, and C17, and resistors R18 and
R19 provide a compensation network for VOUT1 on the
EV kit.
Regulator output VOUT2 is set to 1.5V with resistors
R18 and R19 and provides up to 2A at 84% efficiency.
Capacitors C5, C6, and C7, and resistors R16 and
R17 provide a compensation network for VOUT2 on
the EV kit.
VOUT1 and VOUT2 output voltages can be reconfig-
ured between 0.6V to VIN by replacing the respective
feedback resistors. To reconfigure the regulator out-
puts, refer to the
Compensation Design Guidelines
sec-
tion in the MAX15022 IC data sheet for instructions on
selecting new resistor values. Also refer to the
Effective
Input-Voltage Range
section in the MAX15022 IC data
sheet for the minimum and maximum input-voltage
range when reconfiguring the regulator outputs.
Component changes are necessary for proper opera-
tion after reconfiguring the output voltage. Refer to the
Inductor Selection, Input-Capacitor Selection,
and the
Compensation Design Guidelines
sections in the
MAX15022 IC data sheet to select the proper values.
VOUT3 current capability is restricted by the regulator’s
input power source, the output voltage setting, and
transistor Q1. Verify that Q1 power dissipation rating is
not exceeded when operating the LDO regulator at
high input-to-output voltage differentials and full load.
1.2V Regulator Output (VOUT4)
VOUT4 LDO output is set to 1.2V by feedback resistors
R9 and R10 and provides up to 500mA of output cur-
rent. Jumper JU2 selects the input power source for
VOUT4 or configures VOUT4 for power-supply
sequencing with VOUT2. Install a shunt across pins 1-2
to select VIN as the input power source. Install a shunt
across pins 2-3 to select VOUT2 as the LDO input
power source. Resistors R11 and R12 set the VOUT4
turn-on threshold to 1.3V. See Table 3 for proper
jumper configuration of VOUT4 input power source.
Table 3. VOUT4 Input Power Source (JU2)
SHUNT
POSITION
1-2
2-3
Not
installed
VOUT4 INPUT
POWER SOURCE
VIN
VOUT2
—
EV KIT OPERATION
VOUT4 enabled
VOUT4 enabled
VOUT4 disabled
2.5V LDO Output (VOUT3)
The VOUT3 LDO output is set to 2.5V by feedback
resistors R3 and R4 and provide up to 500mA of output
current. Jumper JU1 selects the input power source for
VOUT3 or configures VOUT3 for power-supply
sequencing with VOUT1. Install a shunt across pins 1-2
to select VIN as the input power source. Install a shunt
across pins 2-3 to select VOUT1 as the LDO input
power source. Resistors R5 and R6 set VOUT3 turn-on
threshold to 3V. See Table 2 for proper jumper configu-
ration of VOUT3 input power source.
To reconfigure VOUT4 to different output voltages, refer
to the
Output 3 and Output 4 Voltage Selection
section in
the MAX15022 IC data sheet for additional information.
VOUT4 current capability is restricted by the regulator’s
input power source, the output voltage setting, and
transistor Q2. Verify that Q2 power dissipation rating is
not exceeded when operating the LDO regulator at
high input-to-output voltage differentials and full load.
Switching Frequency
The MAX15022 switching frequency is set to 2MHz by
resistor R24. Replace resistor R24 with a new resistor
value to program the switching frequency between
500kHz and 4MHz. Use the following equation to select
R24 when reconfiguring the switching frequency:
R24
≅
(8. 36
×
10
−
3
)
×
f
SW
where f
SW
is in hertz and R24 is in ohms.
When reconfiguring the EV kit switching frequency, it is
necessary to replace the compensation network and
power components. Refer to the
Inductor Selection
and
Compensation Design Guidelines
sections in the
MAX15022 IC data sheet for computing new compen-
sation and power component values.
Table 2. VOUT3 Input Power Source (JU1)
SHUNT
POSITION
1-2
2-3
Not
installed
VOUT3 INPUT
POWER SOURCE
VIN
VOUT1
—
EV KIT OPERATION
VOUT3 enabled
VOUT3 enabled
VOUT3 disabled
To reconfigure VOUT3 to different output voltages, refer
to the
Output 3 and Output 4 Voltage Selection
section in
the MAX15022 IC data sheet for additional information.
4
_______________________________________________________________________________________
MAX15022 Evaluation Kit
Evaluates: MAX15022
Figure 1. MAX15022 EV Kit Schematic
_______________________________________________________________________________________
5
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