19-3335; Rev 0; 7/04
MAX1575 Evaluation Kit
General Description
The MAX1575 evaluation kit (EV kit) is a fully assem-
bled and tested circuit for evaluating the MAX1575
white LED 1x/1.5x charge pump. The MAX1575 drives
4 white LEDs in a main display group and 2 white LEDs
in a sub-group. These 6 surface-mount white LEDs are
included on the EV kit. In addition to the LED driver cir-
cuit, the EV kit includes two pulse-generator circuits on
the left side of the PC board that are used for testing
the single-wire serial pulse-dimming feature of the
MAX1575.
Features
♦
Powers 4 Main and 2 Sub-Display LEDs
♦
Average 85% Efficiency (P
LED
/ P
BATT
) over Li+
Battery Discharge
♦
1.5% LED Current Matching
♦
Adaptive 1x/1.5x Mode Switchover
♦
Low Input Ripple and EMI
♦
Individual 5% to 100% Brightness Single-Wire
Serial Pulse Dimming
♦
2.7V to 5.5V Supply Voltage Range
♦
Thin QFN 4mm x 4mm IC Package
♦
Fully Assembled and Tested
Evaluates: MAX1575
Component List
DESIGNATION
QTY
DESCRIPTION
1µF
±20%,
6.3V X5R ceramic
capacitors (0402)
Panasonic ECJ0EB0J105M or
TDK C1005X5R0J105M or
equivalent
2.2µF
±10%,
6.3V X5R ceramic
capacitors (0603)
Panasonic ECJ1VB0J225K or
TDK C1608X5R0J225K or
equivalent
0.01µF
±10%,
X7R ceramic
capacitors (0402)
TDK C1005X7R1E103K or
equivalent
White surface-mount
right-angle LEDs
Nichia NSCW215T
Diodes (SOD-323)
Central CMDD4448
Not installed, PC board short
3-pin headers
6.81kΩ
±1%
resistor (0402)
10kΩ
±5%
resistors (0402)
Momentary pushbutton switches
Panasonic EVQ-PHP03T
Maxim MAX1575ETE
(16 thin QFN 4mm x 4mm)
MAX6818EUS-T (4-pin SOT143)
Shunt, 2 position
C1–C4
4
Ordering Information
PART
MAX1575EVKIT
TEMP RANGE
0°C to +70°C
IC PACKAGE
16 Thin QFN (4mm x 4mm)
C5, C8
2
Quick Start
Recommended Equipment
A 2.7V to 5.5V power supply or battery capable of
delivering 200mA.
C6, C7
2
Procedure
Follow the steps below to verify board operation.
1) Verify that shunts are connected across pins 1-2 of
jumpers JU2 and JU3.
2) Preset the power supply to between 2.7V and 5.5V.
3) Turn off the power supply. Do not turn on the power
supply until all connections are completed.
4) Connect the positive power supply terminal to the
pad on the EV kit labeled IN.
5) Connect the power supply ground terminal to the
pad on the EV kit labeled GND.
6) Turn on the power supply and verify that the LEDs
are lit.
See the
Detailed Description
section for testing the
dimming and shutdown features.
D1–D6
6
D7, D8
JU1
JU2, JU3
R1
R2, R3
S1, S2
U1
U2, U3
—
2
0
2
1
2
2
1
2
2
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MAX1575 Evaluation Kit
Evaluates: MAX1575
Component Suppliers
SUPPLIER
Central Semiconductor
Kamaya
Murata
Nichia
Panasonic
Taiyo Yuden
TDK
Vishay
PHONE
631-435-1110
260-489-1533
814-237-1431
248-352-6575
714-373-7939
408-573-4150
847-803-6100
402-563-6866
WEBSITE
www.centralsemi.com
www.kamaya.com
www.murata.com
www.nichia.com
www.panasonic.com
www.t-yuden.com
www.component.tdk.com
www.vishay.com
Note:
Indicate that you are using the MAX1575 when contacting these component suppliers.
Detailed Description
LED Dimming
To test the dimming feature, press the button labeled
DIM MAIN or DIM SUB. Each of the first nine button
presses dims the corresponding group of LEDs by
10%. The tenth press dims the LEDs by 5%, and the
eleventh press returns the LEDs to full brightness. Refer
to the MAX1575 data sheet for more information on the
dimming feature.
Using External Pulse Generators for Dimming
To use external pulse generators in place of the pulse
generators included with the EV kit, simply connect the
outputs of the external pulse generators to EN_MAIN
for the main display dimming, and EN_SUB for the sub-
display dimming. The grounds of the external pulse
generators should be connected to the EV kit pad
labeled GND. Short pins 1-2 of jumpers JU2 and JU3.
Note that there are 10kΩ pullup resistors from
EN_MAIN and EN_SUB to IN on the EV kit.
Shutdown
Two jumpers are included on the EV kit for shutting
down each of the displays. To turn off the main LED
group, short pins 2-3 of JU2. To turn off the sub-LED
group, short pins 2-3 of JU3. Note that with pins 2-3 of
JU2 or JU3 shorted, power is disconnected from the
corresponding pulse-generator circuit on the left side of
the board. To place the MAX1575 in low-power shut-
down mode and disconnect power from both pulse-
generator circuits, short pins 2-3 of both JU2 and JU3.
Changing the Number of LEDs
The EV kit comes with 6 LEDs installed, 4 for the main
display and 2 for the sub-display. To use fewer LEDs,
locate the small pad next to the LED to be removed and
connect it to the pad on the EV kit labeled IN.
Connecting External LEDs
To connect external LEDs to the MAX1575 EV kit, cut
the trace shorting JU1. Connect the anodes of all the
external LEDs to the small pad labeled OUT. Connect
the cathodes to the small pads next to D1–D6 (D1–D4
for the main LEDs, D5–D6 for the sub-LEDs). Connect
any unused pads (D1–D6) to IN.
Adjusting the 100% Brightness Level
The full-brightness LED current is adjusted by chang-
ing the resistor R1. Calculate the value of R1 with the
following equation, where I
LED_
is the current through
one of the LEDs with the dimming set to 100%.
R1
=
0.6V
×
234
I
LED_
2
_______________________________________________________________________________________
MAX1575 Evaluation Kit
Evaluates: MAX1575
IN
1
2
3
EN_MAIN GND
IN
C1
1µF
16
C1P
14
C3
1µF
IN
13
C1N
OUT
LED1
2
11
D1
OUT
C4
1µF
JU1
JU2
4
V
CC
2
C5
2.2µF
IN
R2
10kΩ
D7
U2
IN
OUT
3
C6
0.01µF
MAX6816
S1
GND
1
12
GND
IN
1
2
3
5
4
R1
6.81kΩ
ENM
U1
LED2
10
D2
JU3
4
V
CC
2
C8
2.2µF
ENS
MAX1575
LED3
9
D3
R3
10kΩ
D8
3
SET
LED4
LED5
8
7
6
D4
D5
D6
U3
IN
OUT
3
C7
0.01µF
C2P
EN_SUB
1
C2
1µF
MAX6816
S2
GND
1
LED6
C2N
15
Figure 1. MAX1575 EV Kit Schematic
_______________________________________________________________________________________
3
MAX1575 Evaluation Kit
Evaluates: MAX1575
Figure 2. MAX1575 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX1575 EV Kit Layout—Component Side
Figure 4. MAX1575 EV Kit Layout—Solder Side
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.
4
_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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