MAX17572 5V Output Evaluation Kit
Evaluates: MAX17572 in 5V
Output-Voltage Application
General Description
The MAX17572 5V output evaluation kit (EV kit) provides
a proven design to evaluate the MAX17572 high-voltage,
high-efficiency, synchronous step-down DC-DC converter.
The EV kit is preset for 5V output at load currents up to
1A and features a 500kHz switching frequency for optimum
efficiency and component size. The EV kit features adjustable
input undervoltage-lockout, adjustable soft-start, open-
drain
RESET
signal, and external frequency synchronization.
Quick Start
●
●
●
●
Recommended Equipment
MAX17572 5V output EV kit
Load capable of sinking 1A
Digital voltmeter (DVM)
6V to 60V, 2A DC input power supply
Procedure
Features
●
●
●
●
●
●
●
●
●
●
●
Operates From a 6V to 60V Input Supply
5V Output Voltage
Up to 1A Output Current
500kHz Switching Frequency
Enable/UVLO Input, Resistor-Programmable UVLO
Threshold
Adjustable Soft-Start Time
Open-Drain
RESET
Output
External Frequency Synchronization
Overcurrent and Overtemperature Protection
Proven PCB Layout
Fully Assembled and Tested
The EV kit is fully assembled and tested. Follow the steps
below to verify the board operation.
Caution: Do not turn
on power supply until all connections are completed.
1)
2)
Set the power supply at a voltage between 6V and
60V. Disable the power supply.
Connect the positive terminal of the power supply
to the V
IN
PCB pad and the negative terminal to
the nearest PGND PCB pad. Connect the positive
terminal of the 1A load to the V
OUT
PCB pad and the
negative terminal to the nearest PGND PCB pad.
Connect the DVM across the V
OUT
PCB pad and
the nearest PGND PCB pad.
Verify that shunts are installed across pins 1-2 on
jumper JU1 (see
Table 1
for details).
Turn on the DC power supply.
Enable the load.
Verify that the DVM displays 5V
3)
4)
5)
Ordering Information
appears at end of data sheet.
6)
7)
19-8650; Rev 0; 9/16
MAX17572 5V Output Evaluation Kit
Evaluates: MAX17572 in 5V
Output-Voltage Application
Connect the center node of the divider to EN/UVLO.
Choose R1 to be 3.3MΩ and then calculate R2 as follows:
R2
=
1.215
×
R1
(V
INU
−
1.215)
Detailed Description of Hardware
The MAX17572 5V output EV kit provides a proven
design to evaluate the MAX17572 high-voltage, high
efficiency, synchronous step-down DC-DC converter.
The EV kit is preset for 5V output from 6V to 60V input at
load currents up to 1A and features a 500kHz switching
frequency for optimum efficiency and component size.
The EV kit includes an EN/UVLO PCB pad and jumper
JU1 to enable the output at a desired input voltage. An
additional RESET PCB pad is available for monitoring
whether the converter output is in regulation.
where V
INU
is the voltage at which the device is required
to turn on. Ensure that V
INU
is higher than 0.8 x V
OUT
.
If the EN/UVLO pin is driven from an external signal source,
a series resistance of minimum 1kΩ is recommended to be
placed between the signal source output and the EN/UVLO
pin, to reduce voltage ringing on the line.
Soft-Start Capacitor Selection
The device implements adjustable soft-start operation to
reduce inrush current. A capacitor connected from the SS
pin to GND programs the soft-start time. The selected
output capacitance (C
SEL
) and the output voltage (V
OUT
)
determine the minimum required soft-start capacitor as
follows:
C
SS
≥
56
×
10
−
6
×
C
SEL
×
V
OUT
The soft-start time (t
SS
) is related to the capacitor
connected at SS (C
SS
) by the following equation:
t
SS
=
5.55
×
10
−
6
C
SS
Adjusting Output Voltage
Set the output voltage with a resistive voltage-divider connected
from the positive terminal of the output capacitor (V
OUT
)
to SGND. Connect the center node of the divider to the FB
pin. Use the following procedure to choose the resistive
voltage-divider values:
Calculate resistor R4 from the output to the FB pin as
follows:
R3
=
1850
C
OUT_SEL
For example, to program a 2ms soft-start time, a 12nF
capacitor should be connected from the SS pin to GND.
Setting the Undervoltage-Lockout Level
The device offers an adjustable input undervoltage-lockout
level. Set the voltage at which the device turns on with
a resistive voltage-divider connected from V
IN
to SGND.
Where C
OUT_SEL
(in µF) is the actual derated value of
the output capacitance used and R3 is in kΩ. The minimum
allowable value of R3 is (5.6 x V
OUT
), where R3 is in kΩ.
If the value of R3 calculated using the above equation
is less than (5.6 x V
OUT
), increase the value of R3 to at
least (5.6 x V
OUT
).
R4
=
R3 is in kΩ.
R3
×
0.9
(V
OUT
−
0.9)
Table 1. TBD
SHUNT POSITION
1-2*
Not installed
2-3
EN/UVLO PIN
Connected to VIN
Connected to the center node of
resistor-divider R1 and R2
Connected to SGND
MAX17572_ OUTPUT
Enabled
Enabled, UVLO level set through
the R1 and R2 resistors
Disabled
www.maximintegrated.com
Maxim Integrated
│
2
MAX17572 5V Output Evaluation Kit
Evaluates: MAX17572 in 5V
Output-Voltage Application
VIN
R1
EN/UVLO
R2
SGND
R4
SGND
R3
V
OUT
FB
Figure 1. Setting the Input Undervoltage Lockout
Figure 2: Adjusting Output Voltage
EV Kit Performance Report
MAX17572, 5V OUTPUT, PWM MODE,
LOAD AND LINE REGULATION
FIGURE 4 CIRCUIT
MAX17572, 5V OUTPUT, PWM MODE,
EFFICIENCY VS. LOAD CURRENT
FIGURE 4 CIRCUIT
toc02
5.04
5.03
OUTPUT VOLTAGE (V)
toc01
100
90
EFFICIENCY (%)
V
IN
= 24V
5.02
5.01
V
IN
= 12V
5.00
4.99
V
IN
= 36V
V
IN
= 48V
80
70
60
50
40
V
IN
= 12V
V
IN
= 24V
V
IN
= 36V
V
IN
= 48V
MODE = SGND
0
200
400
600
800
1000
30
MODE = SGND
0
200
400
600
800
1000
LOAD CURRENT (mA)
LOAD CURRENT (mA)
www.maximintegrated.com
Maxim Integrated
│
3
MAX17572 5V Output Evaluation Kit
Evaluates: MAX17572 in 5V
Output-Voltage Application
EV Kit Performance Report (continued)
MAX17572, 5V OUTPUT, 1A LOAD CURRENT,
BODE PLOT, FIGURE 4 CIRCUIT
toc03
MAX17572, 5V OUTPUT, PWM MODE, FIGURE 4
CIRCUIT (LOAD CURRENT STEPPED
toc04
FROM NO LOAD TO 0.5A)
PHASE
V
OUT
AC
PHASE (°)
100mV/div
GAIN (dB)
GAIN
CROSSOVER FREQUENCY = 47.9KHz,
PHASE MARGIN = 70.5°
I
LOAD
100μS/div
500mA/div
FREQUENCY (Hz)
MAX17572, 5V OUTPUT, PWM MODE, FIGURE 4
CIRCUIT (LOAD CURRENT STEPPED
toc05
FROM 0.5A TO 1A
V
OUT
AC
100mV/div
I
LOAD
100μS/div
500mA/div
Component Suppliers
SUPPLIER
Coilcraft, Inc.
Murata Americas
Panasonic Corp.
Vishay
Onsemi
WEBSITE
www.coilcraft.com
www.murata.com
www.panasonic.com
www.vishay.com
www.onsemi.com
Note:
Indicate that you are using the MAX17572 when contacting these component suppliers.
Ordering Information
PART
MAX17572EVKITB#
TYPE
EV KIT
www.maximintegrated.com
Maxim Integrated
│
4
MAX17572 5V Output Evaluation Kit
Evaluates: MAX17572 in 5V
Output-Voltage Application
MAX17572 EV System Bill of Materials
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
DESCRIPTION
2.2uF 10%, 100V ,X7R,
Ceramic capacitor (1210)
10uF 10%, 10V ,X7R,
Ceramic capacitor (1210)
33uF,20%,80V,
ELECT,10mm
1uF 10%, 6.3V ,X7R,
Ceramic capacitor (0603)
5600pF,10%,50V,X7R,0402,
Ceramic capacitor(0402)
0.1uF,10%,50V,X7R,
Ceramic capacitor(0402)
47pF,10%,50V,X7R,0402,
Ceramic capacitor(0402)
100pF,10%,50V,X7R,0402,
Ceramic capacitor(0402)
0.1uF,10%,100V,X7R,0603,
Ceramic capacitor(0603)
Diode PIV=20V; IF=0.5A
3-pin header
(36-pin header 0.1” centers )
INDUCTOR, 15uH, 2.8A
RES+,3.32MOHM,1%,0402
RES+,604K OHM,1%,0402
RES+,178K OHM,1%,0402
RES+, 39KOHM,1%,0402
RES+, 4.7OHM,1%,0402
RES+,100K OHM,1%,0402
RES+,40.2K OHM,1%,0402
RES+,1K OHM,1%,0402
Buck Converter
MAX17572ATJ+
3 pin headers
QUANTITY
1
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
DESIGNATOR
C1
C2
C3
C4
C5
C6,C7
C8
C9
C10
D1
JU1
L1
R1
R2
R3
R4
R5
R6
R7
R8
U1
See Jumper
Table1
MAX17572ATJ+
SULLINS STC02SYAN
PART NUMBER
MURATA GRM32ER72A225KA35
MURATA GRM32DR71A106KA01
PANASONIC EEE-FK1K330P
MURATA GRM188R70J105KA01
KEMET C0402C562K5RAC
MURATA GRM155R71H104KE14
MURATA GRM1555C1H470JA01
KEMET C0402C101K5GAC,
TDKC1005C0G1H101K050BA
MURATA GRM188R72A104KA35
ON SEMICONDUCTOR
NSR05F20NXT5G
Sullins: PTC36SAAN
COILCRAFT XAL4040-153ME
www.maximintegrated.com
Maxim Integrated
│
5
京公网安备 11010802033920号
EEWORLD
