Maxim Integrated MAX17127EVKIT+ User guide
19-5449; Rev 0; 7/10
MAX17127 Evaluation Kit
General Description
The MAX17127 evaluation kit (EV kit) is a fully assembled
and tested surface-mount PCB that evaluates the highefficiency 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 surfacemount 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.
Evaluates: MAX17127
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
PART TYPE
MAX17127EVKIT+ EV Kit
+Denotes lead(Pb)-free and RoHS compliant.
Component List
DESIGNATION QTY DESCRIPTION
0.1FF Q10%, 50V X7R ceramic
C1 1
C2–C8,
C10–C16, C24
C9 1
C17 1
C18, C22, C23 0
C19, C21 2
C20 1
capacitor (0603)
Murata GRM188R71H104K
TDK C1608X7R1H104K
Not installed, ceramic capacitors
0
(0603)
510pF Q5%, 50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H511J
AVX 06035A511JA12A
1FF Q10%, 10V X7R ceramic
capacitor (0603)
Taiyo Yuden LMK107BJ105KA
Murata GRM188R71A105K
Not installed, ceramic capacitors
(1206)
2.2FF Q20%, 50V X7R ceramic
capacitors (1206)
Murata GRM31CR71H225K
4.7FF Q10%, 25V X5R ceramic
capacitor (1206)
Murata GRM319R61E475K
DESIGNATION QTY DESCRIPTION
0.7A, 60V Schottky diode
D1 1
D2–D61 60
JU1, JU6,
JU8–JU12
JU2 0
JU7 0
JU4,
JU13–JU19,
JU20, JU21
L1 1
R1, R8, R10 3
R2 1
R3 1
R4 1
(US Flat)
Toshiba CUS04
White LEDs
Nichia NSSW008CT-P1
OPTEK OVSRWACR6
7 3-pin headers
Not installed, 2-pin header—
short PC trace
Not installed, 3-pin header
(pins 2-3—short PC trace)
10 2-pin headers
10FH, 1.2A power inductor
Sumida CR6D09HPNP-100MC
TDK VLP6810T-100M1R2
100kI Q5% resistors (0603)
1MI Q5% resistor (0603)
0I Q5% resistor (0603)
10kI Q5% resistor (0603)
_______________________________________________________________ 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.
MAX17127 Evaluation Kit
Component List (continued)
DESIGNATION QTY DESCRIPTION
R5 1
R6 1
R7 1
R11 0 Not installed, resistor (0603)
R12 0
R14 2
82.5kI Q1% resistor (0603)
2.21MI Q1% resistor (0603)
71.5kI Q1% resistor (0603)
Not installed, multiturn
potentiometer
500kI multiturn potentiometer
DESIGNATION QTY DESCRIPTION
Six-string WLED driver
U1 1
— 17 Shunts
— 1
*EP = Exposed pad.
(20 TQFN-EP*)
Maxim MAX17127ETP+
PCB: MAX17127 EVALUATION
KIT+
Component Suppliers
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
Evaluates: MAX17127
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
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.
Table 1. Default Shunt Positions
JUMPER SHUNT POSITION
JU1, JU6, JU8–JU12 1-2
JU4, JU14, JU15,
JU17–JU20, JU21
JU13, JU16 Installed
Not installed
Detailed Description of Hardware
The MAX17127 evaluation kit (EV kit) operates on a 5V
to 26V wide-input voltage range and provides adjustable 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 surfacemount WLEDs.
2 ______________________________________________________________________________________
MAX17127 Evaluation Kit
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 jumpers 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 component changes. Refer to the MAX17127 IC data sheet for
component selections.
Enable (EN)
The EV kit features 2-pin jumper JU16 to control the activelow 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.
Table 2. Jumper Function (JU1, JU8–JU12)
SHUNT
POSITION
1-2*
2-3 Connected to AGND Disabled
Not installed
*Default position.
FB_ PIN STRING_
Connected to cathode
of WLED string
Connect to an external
WLED string
Enabled
On-board WLED
string not used
Table 3. Jumper Function (JU13)
SHUNT POSITION VOUT
Installed*
Not installed
*Default position.
Connected to anodes of on-board
WLED strings
Connect to anodes of off-board
WLED strings
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) capacitor (C
) is placed in parallel with each LED string to
LED
improve ESD immunity. As such, the EV kit provides a
footprint across each LED string for optional C
LED
.
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:
I 20 mA
LED(MAX)
= ×
R8 R14
+
Ω
180k
where R8 is a 100kI resistor and R14 is a 500kI potentiometer. 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:
100k
Ω
f 1 MHz
= ×
SW
R10
Changing the switching frequency might require different converter components (refer to the MAX17127 IC
data sheet for proper component selections).
Table 4. Jumper Function (JU16)
SHUNT
POSITION
Installed* Connected to VDDIO Enabled
Not installed Internally connected to AGND Disabled
*Default position.
EN PIN MAX17127
Evaluates: MAX17127
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