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For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
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MAX17127 Evaluation Kit
Evaluates: MAX17127
General Description
The MAX17127 evaluation kit (EV kit) is a fully assembled
and tested surface-mount PCB that evaluates the high-
efficiency MAX17127 white LED (WLED) driver. The EV
kit utilizes a step-up DC-DC converter to generate the
voltage required to drive up to six strings of 10 surface-
mount WLEDs. The EV kit uses a 5V to 26V input power
supply and can be configured to provide an adjustable
10mA to 30mA full-scale LED current.
Features
S 5V to 26V Input Range
S WLED Drives Up to 30mA/String
S Drives Six Strings of 10 WLEDs
S Full-Scale LED Current Adjustable from 10mA to
30mA
S 1MHz PWM Switching Frequency Adjustable from
250kHz to 1MHz (Component Change Required)
S All Components < 1mm Height
S Fully Assembled and Tested
Ordering Information
19-5449; Rev 0; 7/10
+Denotes lead(Pb)-free and RoHS compliant.
Component List
PART TYPE
MAX17127EVKIT+ EV Kit
DESIGNATION QTY DESCRIPTION
C1 1
0.1FF Q10%, 50V X7R ceramic
capacitor (0603)
Murata GRM188R71H104K
TDK C1608X7R1H104K
C2–C8,
C10–C16, C24 0Not installed, ceramic capacitors
(0603)
C9 1
510pF Q5%, 50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H511J
AVX 06035A511JA12A
C17 1
1FF Q10%, 10V X7R ceramic
capacitor (0603)
Taiyo Yuden LMK107BJ105KA
Murata GRM188R71A105K
C18, C22, C23 0 Not installed, ceramic capacitors
(1206)
C19, C21 2
2.2FF Q20%, 50V X7R ceramic
capacitors (1206)
Murata GRM31CR71H225K
C20 1
4.7FF Q10%, 25V X5R ceramic
capacitor (1206)
Murata GRM319R61E475K
DESIGNATION QTY DESCRIPTION
D1 1
0.7A, 60V Schottky diode
(US Flat)
Toshiba CUS04
D2–D61 60
White LEDs
Nichia NSSW008CT-P1
OPTEK OVSRWACR6
JU1, JU6,
JU8–JU12 7 3-pin headers
JU2 0 Not installed, 2-pin header—
short PC trace
JU7 0 Not installed, 3-pin header
(pins 2-3—short PC trace)
JU4,
JU13–JU19,
JU20, JU21
10 2-pin headers
L1 1
10FH, 1.2A power inductor
Sumida CR6D09HPNP-100MC
TDK VLP6810T-100M1R2
R1, R8, R10 3 100kI Q5% resistors (0603)
R2 1 1MI Q5% resistor (0603)
R3 1 0I Q5% resistor (0603)
R4 1 10kI Q5% resistor (0603)
MAX17127 Evaluation Kit
Evaluates: MAX17127
2 ______________________________________________________________________________________
*EP = Exposed pad.
Component List (continued)
Component Suppliers
Note: Indicate that you are using the MAX17127 when contacting these component suppliers.
Quick Start
Recommended Equipment
• MAX17127 EV kit
• 5V to 26V power supply (VIN)
Procedure
The 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) On the EV kit, verify that the shunts are installed, as
shown in Table 1.
2) Connect the positive terminal of the VIN power
supply to the VIN pad. Connect the ground terminal
of the VIN power supply to the PGND pad.
3) Set the VIN power supply to 12V and enable its output.
4) Verify that the six strings of WLEDs are on.
Detailed Description of Hardware
The MAX17127 evaluation kit (EV kit) operates on a 5V
to 26V wide-input voltage range and provides adjust-
able 10mA to 30mA full-scale LED current. The EV kit
utilizes a step-up DC-DC converter to generate the
voltage required to drive up to six strings of 10 surface-
mount WLEDs.
Table 1. Default Shunt Positions
SUPPLIER PHONE WEBSITE
AVX Corporation 843-946-0238 www.avxcorp.com
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
Nichia Corp. 248-352-6575 www.nichia.com
OPTEK Technologies 972-323-2200 www.optekinc.com
Sumida Corp. 847-545-6700 www.sumida.com
Taiyo Yuden 800-348-2496 www.t-yuden.com
TDK Corp. 847-803-6100 www.component.tdk.com
Toshiba America Electronic Components, Inc. 949-623-2900 www.toshiba.com/taec
DESIGNATION QTY DESCRIPTION
R5 1 82.5kI Q1% resistor (0603)
R6 1 2.21MI Q1% resistor (0603)
R7 1 71.5kI Q1% resistor (0603)
R11 0 Not installed, resistor (0603)
R12 0 Not installed, multiturn
potentiometer
R14 2 500kI multiturn potentiometer
DESIGNATION QTY DESCRIPTION
U1 1
Six-string WLED driver
(20 TQFN-EP*)
Maxim MAX17127ETP+
— 17 Shunts
— 1 PCB: MAX17127 EVALUATION
KIT+
JUMPER SHUNT POSITION
JU1, JU6, JU8–JU12 1-2
JU4, JU14, JU15,
JU17–JU20, JU21 Not installed
JU13, JU16 Installed
MAX17127 Evaluation Kit
Evaluates: MAX17127
_______________________________________________________________________________________ 3
Table 3. Jumper Function (JU13)
Table 2. Jumper Function (JU1, JU8–JU12)
*Default position.
*Default position.
White LED String Configuration
As configured, the EV kit is assembled with six strings of
10 WLEDs. Each string has an associated 3-pin header
(JU1, JU8–JU12) and feedback pin (FB1–FB6). The
function of the 3-pin jumpers is summarized in Table 2.
To evaluate the EV kit with off-board WLED strings, see
the Off-Board WLED String Configuration section.
Off-Board WLED String Configuration
The EV kit can also be used to drive off-board WLED
strings. To evaluate external WLED strings, reconfigure
shunts from jumpers JU1 and JU8–JU12. See Table 2
for jumpers JU1 and JU8–JU12 configuration and Table
3 for jumper JU13 configuration. Removing these jump-
ers effectively disconnects the on-board WLED strings
between the output and feedback pins, allowing the
connection of external WLED strings. For each external
WLED string, connect the cathode terminal of the string to
the corresponding feedback pad (FB1–FB6) and connect
the anode terminal of the string to the VOUT pad. Once the
external WLED strings are connected between the VOUT
pad and the FB1–FB6 pins, the EV kit can be evaluated in
the same manner as the on-board WLED strings. Evaluating
more than 10 WLEDs per string may require compo-
nent changes. Refer to the MAX17127 IC data sheet for
component selections.
Enable (EN)
The EV kit features 2-pin jumper JU16 to control the active-
low shutdown input. Drive EN high to place the device in
normal operation. If the JU16 shunt is removed, an internal
200kI (typ) pulldown resistor places the device in disabled
mode. See Table 4 for shunt positions.
Brightness Control by PWM
Signal Input (PWM)
The EV kit features 2-pin jumper JU20 to implement
brightness control through the PWM signal input. See
Table 5 for shunt positions.
LED String Capacitance
In some LCD panel applications, a 0.1FF (typ) capaci-
tor (CLED) is placed in parallel with each LED string to
improve ESD immunity. As such, the EV kit provides a
footprint across each LED string for optional CLED.
Full-Scale LED Current Adjustment (ISET)
The EV kit features 3-pin jumper JU6, along with R8 and
R14, to set the full-scale LED current. The resistance
from ISET to AGND controls the full-scale current in each
LED string according to the following equation:
LED(MAX)
180k
I 20 mA
R8 R14
Ω
= ×
+
where R8 is a 100kI resistor and R14 is a 500kI poten-
tiometer. See Table 6 for jumper JU6 settings.
Switching-Frequency Selection (FSLCT)
The EV kit is configured to operate at 1MHz, but provides
the option to set the switching frequency of the step-up
DC-DC converter from 250kHz to 1MHz. The switching
frequency is set by adjusting the resistance from FSLCT
to AGND according to the following equation:
SW 100k
f 1 MHz R10
Ω
= ×
Changing the switching frequency might require differ-
ent converter components (refer to the MAX17127 IC
data sheet for proper component selections).
Table 4. Jumper Function (JU16)
*Default position.
SHUNT
POSITION EN PIN MAX17127
Installed* Connected to VDDIO Enabled
Not installed Internally connected to AGND Disabled
SHUNT
POSITION FB_ PIN STRING_
1-2* Connected to cathode
of WLED string Enabled
2-3 Connected to AGND Disabled
Not installed Connect to an external
WLED string
On-board WLED
string not used
SHUNT POSITION VOUT
Installed* Connected to anodes of on-board
WLED strings
Not installed Connect to anodes of off-board
WLED strings
MAX17127 Evaluation Kit
Evaluates: MAX17127
4 ______________________________________________________________________________________
Table 5. Jumper Function (JU20) Table 6. Jumper Function (JU6)
*Default position.
*Default position.
SHUNT
POSITION PWM PIN PWM DUTY CYCLE
OF LED CURRENT
Installed Connected to AGND Zero
Not
installed*
Connected to VDDIO
through R2 Maximum (100%)
Not
installed
Connect to an exter-
nal PWM signal
(0.1kHz to 25kHz)
Follows the signal
applied at PWM pad
SHUNT
POSITION ISET PIN ILED(MAX)
1-2* Connected to AGND
through R8 and R14
Adjustable from
10mA to 30mA
2-3 Connected to AGND 0.3mA (typ)
MAX17127 Evaluation Kit
Evaluates: MAX17127
_______________________________________________________________________________________ 5
Figure 1. MAX17127 EV Kit Schematic
MAX17127 Evaluation Kit
Evaluates: MAX17127
6 ______________________________________________________________________________________
Figure 2. MAX17127 EV Kit Component Placement Guide—Component Side
1.0’’
MAX17127 Evaluation Kit
Evaluates: MAX17127
_______________________________________________________________________________________ 7
Figure 3. MAX17127 EV Kit PCB Layout—Component Side
1.0’’
MAX17127 Evaluation Kit
Evaluates: MAX17127
8 ______________________________________________________________________________________
Figure 4. MAX17127 EV Kit PCB Layout—Solder Side
1.0’’
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 9
© 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX17127 Evaluation Kit
Evaluates: MAX17127
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 7/10 Initial release —
