MPS EV1518DG-00A User manual

EV1518DG-00A
Fixed Frequency WLED Driver
Evaluation Board
EV1518DG-00A Rev. 1.2 www.MonolithicPower.com 1
10/17/2007 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2007 MPS. All Rights Reserved.
The Future of Analog IC Technology
TM
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GENERAL DESCRIPTION
The EV1518DG-00A is an evaluation board for
the MP1518, a step-up converter designed for
driving up to 6 series white LEDs from a single
cell Lithium Ion battery. The MP1518 uses
current mode, fixed frequency architecture to
regulate the LED current, which is measured
through an external current sense resistor. Its
low 104mV feedback voltage reduces power
loss and improves efficiency. The OV pin
monitors the output voltage and turns off the
converter if an over-voltage condition is present
due to an open circuit condition.
The MP1518 includes under-voltage lockout,
current limiting and thermal overload protection
preventing damage in the event of an output
overload.
ELECTRICAL SPECIFICATIONS
Parameter Symbol Value Units
Input Voltage VIN 2.5 – 6.0 V
# of WLEDs Up to 6
LED Current ILED 20 mA
FEATURES
•On Board Power MOSFET
•Drives up to 6 Series White LEDs
•Up to 87% Efficiency
•Over 1MHz Fixed Switching Frequency
•Open Load Shutdown
•Low 104mV Feedback Voltage
•Soft Start/PWM Dimming
•UVLO, Thermal Shutdown
•Internal Current Limit
APPLICATIONS
•Cell Phones
•Handheld Computers and PDAs
•Digital Still Cameras
•Small LCD Displays
“MPS” and “The Future of Analog IC Technology” are Trademarks of Monolithic
Power Systems, Inc.
EV1518DG-00A EVALUATION BOARD
(L x W x H) 2.0” x 1.8” x 0.4”
(5.0cm x 4.5cm x 1.0cm)
Board Number MPS IC Number
EV1518DG-00A MP1518DG
88
86
84
82
80
78
76
EFFICIENCY (%)
5 101520
LED CURRENT (mA)
Efficiency vs
LED Current
6 LEDS
3 LEDS
VIN = 3.6V
4 LEDS

EV1518DG-00A – FIXED FREQUENCY WLED DRIVER EVALUATION BOARD
EV1518DG-00A Rev. 1.2 www.MonolithicPower.com 2
10/17/2007 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2007 MPS. All Rights Reserved.
TM
EVALUATION BOARD SCHEMATIC
VIN
EN
GND
LED1
D1
BAT54WS-7
LED2
LED3
LED4
LED5
LED6
U1
MP1518
SWIN
FB
OV
NC
EN
28
3
6
7
5
1
4
GND
GND
EV1518DG-00A BILL OF MATERIALS
Qty Ref Value Description Package Manufacturer Manufacturer P/N
1 C1 4.7µF
Ceramic Capacitor,
6.3V, X5R 0805 TDK C2012X5R0J475M
1 C2 0.22µF
Ceramic Capacitor, 50V,
X7R 1206 TDK C3216X7R1H224K
1 D1
Diode Schottky, 30V,
200mW SOD-323 Diodes Inc BAT54WS-7
1 L1 22µH 400mA SMD Sumida CDRH3D16-220NC
6
LED1, LED2,
LED3, LED4,
LED5, LED6
Not Stuffed
1 R1 100kΩResistor, 5% 0805 Panasonic ERJ-6GEYJ104V
1 R2 4.99ΩResistor, 1% 0805 Yageo 9C08052A4R99FKHFT
1 U1 White Led Driver QFN8
(2x2) MPS MP1518DG

EV1518DG-00A – FIXED FREQUENCY WLED DRIVER EVALUATION BOARD
NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third
party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not
assume any legal responsibility for any said applications.
EV1518DG-00A Rev. 1.2 www.MonolithicPower.com 3
10/17/2007 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2007 MPS. All Rights Reserved.
TM
PRINTED CIRCUIT BOARD LAYOUT
Figure 1—Top Silk Layer Figure 2—Top Layer
Figure 3—Bottom Layer
QUICK START GUIDE
1. Solder LED1 – LED6 to board.
2. Connect the positive and negative terminals of the power supply (2.5V to 6V) to the VIN and
GND pins, respectively.
3. This board is set up for automatic startup. Pull EN low to shut down the MP1518.
4. To use burst mode brightness control, drive EN with a PWM signal.