MAX17501A / MAX17501E Evaluation Kits
Evaluate: MAX17501A/MAX17501E
in TDFN Packages
General Description
The MAX17501A/MAX17501E evaluation kits (EV kits)
provide proven designs to evaluate the MAX17501A/
MAX17501E high-efficiency, high-voltage, synchronous
step-down DC-DC converters. The EV kits use these
devices to generate a fixed 3.3V, at load currents
up to 500mA, from a 4.5V to 60V input supply. The
MAX17501A supports a PFM control scheme with high
light-load efficiency, while the MAX17501E features a
forced-PWM control scheme that provides constant
switching-frequency operation at all load and line condi-
tions.
S
3.3V Fixed Output Voltage
S
500mA Output Current
S
600kHz Switching Frequency
S
Enable/UVLO Input
S
Resistor-Programmable UVLO Threshold
S
Open-Drain
RESET
Output
S
Overcurrent and Overtemperature Protection
S
PFM/PWM (MAX17501A EV Kit)
S
PWM (MAX17501E EV Kit)
S
Proven PCB Layout
Ordering Information
appears at end of data sheet.
Features
S
Operates from a 4.5V to 60V Input Supply
S
Fully Assembled and Tested
Component List
DESIGNATION
C1
QTY
1
DESCRIPTION
1FF
Q10%,
100V X7R ceramic
capacitor (1206)
Murata GRM31CR72A105KA01L
1FF
Q10%,
6.3V X7R ceramic
capacitor (0603)
Murata GRM188R70J105K
3300pF
Q10%,
50V X7R ceramic
capacitor (0402)
Murata GRM155R71H332K
10FF
Q10%,
10V X7R ceramic
capacitor (1206)
Murata GRM31CR71A106K
33FF, 80V aluminum
electrolytic (D = 8mm)
Panasonic EEEFK1K330P
DESIGNATION
JU1
L1
R1
R2
R4
R6
TP1, TP2
U1
—
—
QTY
1
1
1
1
1
1
0
1
1
1
DESCRIPTION
3-pin header
33FH, 1.4A inductor
(6mm x 6mm x 3.5mm)
Coilcraft LPS6235-333ML
3.32MI
Q1%
resistor (0402)
866kI
Q1%
resistor (0402)
100I resistor (0402)
10kI
Q1%
resistor (0402)
Not installed, test points
See the
EV Kit-Specific
Component List
Shunt
PCB: See the
EV Kit-Specific
Component List
C2
1
C3
1
C4
1
C7
1
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.
19-6435; Rev 1; 10/13
MAX17501A /MAX17501E Evaluation Kits
Evaluate: MAX17501A/MAX17501E
in TDFN Packages
EV Kit-Specific Component List
EV KIT
MAX17501ATEVKIT#
DESIGNATION
U1
—
MAX17501ETEVKIT#
*EP
= Exposed pad.
U1
—
DESCRIPTION
Buck converter (10 TDFN-EP*)
Maxim MAX17501AATB+
PCB: MAX17501AT EVALUATION KIT
Buck converter (10 TDFN-EP*)
Maxim MAX17501EATB+
PCB: MAX17501ET EVALUATION KIT
Component Suppliers
SUPPLIER
Coilcraft, Inc.
Murata Electronics North America, Inc.
Panasonic Corp.
PHONE
847-639-6400
770-436-1300
800-344-2112
WEBSITE
www.coilcraft.com
www.murata-northamerica.com
www.panasonic.com
Note:
Indicate that you are using the MAX17501 when contacting these component suppliers.
Quick Start
• MAX17501A or MAX17501E EV kit
• Load capable of sinking 500mA
• Digital voltmeter (DVM)
• Function generator
The EV kits are fully assembled and tested. Follow the steps
below to verify board operation. Caution:
Do not turn on
power supply until all connections are completed.
1) Set the power supply at a voltage between 4.5V and
60V. Disable the power supply.
2) Connect the positive terminal of the power supply
to the VIN PCB pad and the negative terminal to the
nearest PGND PCB pad. Connect the positive termi-
nal of the 500mA load to the VOUT PCB pad and the
negative terminal to the nearest PGND PCB pad.
3) Connect the DVM across the VOUT PCB pad and the
nearest PGND PCB pad.
4) Verify that a shunt is installed across pins 1-2 on
jumper JU1.
5) Turn on the DC power supply.
6) Enable the load.
7) Verify that the DVM displays the expected voltage.
To turn on/turn off the part from EN/UVLO, follow the
steps below:
1) Remove resistors R1 and R2 and the jumper installed
across pins 1-2 on jumper JU1.
2) Connect the power supply to the EV kit and turn on
the power supply. Set the power supply at a voltage
between 4.5V and 60V.
3) Connect the function generator output to the
EN/UVLO test loop.
Recommended Equipment
• 4.5V to 60V, 1A DC input power supply
Procedure
4) EN/UVLO rising threshold is 1.24V and falling thresh-
old is 1.11V. Make sure that the voltage-high and
voltage-low levels of the function generator output are
greater than 1.24V and less than 1.11V, respectively.
5) When powering down the EV kits, first disconnect the
function generator output from the EN/UVLO test loop
and then turn off the DC power supply.
Care should be taken in board layout and systems wiring
to prevent violation of the absolute maximum rating of the
FB/VO pin under short-circuit conditions. Under such con-
ditions, it is possible for the ceramic output capacitor to
oscillate with the board or wiring inductance between the
capacitor and short-circuited load, and thereby cause the
absolute maximum rating of FB/VO (-0.3V) to be exceed-
ed. This parasitic board or wiring inductance should be
minimized and the output voltage waveform under short-
circuit operation should be verified to ensure that the
absolute maximum rating of FB/VO is not exceeded.
2
MAX17501A /MAX17501E Evaluation Kits
Evaluate: MAX17501A/MAX17501E
in TDFN Packages
Detailed Description of Hardware
The MAX17501A/MAX17501E EV kits provide proven
designs to evaluate the MAX17501A/MAX17501E high-
efficiency, high-voltage, synchronous step-down DC-DC
converters. The EV kits generate a fixed 3.3V, at load
currents up to 500mA, from a 4.5V to 60V input sup-
ply. The EV kits feature a 600kHz fixed switching fre-
quency for optimum efficiency and component size. The
MAX17501A EV kit supports a PFM control scheme with
high light-load efficiency, while the MAX17501E EV kit
features a forced-PWM control scheme that provides
constant switching-frequency operation at all load and
line conditions.
The EV kits include an EN/UVLO PCB pad and jumper
JU1 to enable control of the converter output. An
additional
RESET
PCB pad is available for monitor-
ing the converter output. The VCC PCB pad helps
measure the internal LDO voltage.
The devices utilize an adjustable soft-start function to
limit inrush current during startup. The soft-start time is
adjusted by the value of C3, the external capacitor from
SS to GND. To adjust the soft-start time, determine C3
using the following formula:
C3 = 5.55 x t
SS
where t
SS
is the required soft-start time in milliseconds
and C3 is in nanofarads.
The devices feature an EN/UVLO input. For normal
operation, a shunt should be installed across pins 1-2 on
jumper JU1. To disable the output, install a shunt across
pins 2-3 on JU1 and the EN/UVLO pin is pulled to GND.
See Table 1 for JU1 settings.
The devices offer an adjustable input undervoltage-
lockout level. Set the voltage at which the device turns
on with a resistive voltage-divider connected from VIN to
GND. Connect the center node of the divider to EN/UVLO.
Choose R1 to be 3.3MI
and then calculate R2 as follows:
R2
=
R1
×
1.218
(V
INU
−
1.218)
Regulator Enable/Undervoltage-
Lockout Level (EN/UVLO)
Setting the Undervoltage-Lockout Level
Soft-Start Input (SS)
where V
INU
is the voltage at which the device is required
to turn on.
Table 1. Regulator Enable (EN/UVLO) Jumper JU1 Settings
SHUNT POSITION
1-2*
Not installed
2-3
*Default
position.
EN/UVLO PIN
Connected to IN
Connected to the center node of
resistor-divider R1 and R2
Connected to GND
MAX17501_ OUTPUT
Enabled
Enabled, UVLO level set
through the R1 and R2 resistor-divider
Disabled
3
MAX17501A /MAX17501E Evaluation Kits
Evaluate: MAX17501A/MAX17501E
in TDFN Packages
EV Kits Performance Report
LOAD AND LINE REGULATION
(MAX17501A)
3.45
100
90
OUTPUT VOLTAGE (V)
3.40
EFFICIENCY (%)
80
EFFICIENCY vs. LOAD CURRENT
(MAX17501A)
3.35
VIN = 36V
VIN = 24V
VIN = 12V
70
60
VIN = 36V
50
3.30
VIN = 24V
40
VIN = 12V
1
10
100
3.25
0
50 100 150 200 250 300 350 400 450 500
LOAD CURRENT (mA)
30
LOAD CURRENT (mA)
Figure 1. MAX17501A Load and Line Regulation
Figure 3. MAX17501A Efficiency
LOAD AND LINE REGULATION
(MAX17501E)
3.320
3.315
OUTPUT VOLTAGE (V)
EFFICIENCY (%)
3.310
3.305
3.300
3.295
3.290
0
50 100 150 200 250 300 350 400 450 500
LOAD CURRENT (mA)
95
90
85
80
75
70
65
60
55
50
45
EFFICIENCY vs. LOAD CURRENT
(MAX17501E)
VIN = 24V
VIN = 12V
VIN = 36V
VIN = 12V
VIN = 24V
VIN = 36V
50 100 150 200 250 300 350 400 450 500
LOAD CURRENT (mA)
Figure 2. MAX17501E Load and Line Regulation
Figure 4. MAX17501E Efficiency
4
MAX17501A /MAX17501E Evaluation Kits
Evaluate: MAX17501A/MAX17501E
in TDFN Packages
EV Kits Performance Report (continued)
V
OUT
(AC)
50mV/div
f
CR
= 51kHz
PM = 55°
I
OUT
100mA/div
4
5
6 7 8 9 1
2
20µs/div
Figure 5. MAX17501A/MAX17501E Full-Load Bode Plot
(VIN = 24V)
Figure 7. MAX17501E No Load to 250mA Load Transient
V
OUT
(AC)
100mV/div
V
OUT
(AC)
50mV/div
I
OUT
200mA/div
I
OUT
100mA/div
200µs/div
20µs/div
Figure 6. MAX17501A 5mA to 255mA Load Transient
Figure 8. MAX17501A/MAX17501E 250mA to 500mA Load
Transient
5
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