EV0022 (MP1522)
Precision 6 White LED Driver
Evaluation Board
EV0022 Rev. 1.2 www.MonolithicPower.com 1
9/1/2006 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2006 MPS. All Rights Reserved.
The Future of Analog IC Technology
DESCRIPTION
The EV0022 evaluation board uses the
MP1522 to drive up to six (6) series white LEDs
from a single cell Lithium Ion battery. The
MP1522 uses a current limited, variable
frequency architecture to regulate the LED
current, which is measured through an external
current sense resistor. Its 1.23V, 3% feedback
threshold improves the LED current regulation.
The BIAS pin can measure the output voltage
and turn off the converter to prevent damage in
an open circuit condition.
The MP1522 includes under-voltage lockout,
current limiting and thermal overload protection
preventing damage in the event of an output
overload. The MP1522 is available in tiny 5-pin
SOT23 packages.
ELECTRICAL SPECIFICATION
Parameter Symbol Value Units
Input Voltage VCC 3.0 – 5.5 V
LED Current 20 mA
FEATURES
• Internal 0.5Ω Power Switch
• Output Voltage up to 25V
• Up to 90% Efficiency
• Low 1µA Shutdown Current
• Input Under-Voltage Protection
• Thermal Shutdown
• Internal Current Limit
APPLICATIONS
• Handheld Computers, PDAs
• Cell Phones
• Digital Still and Video Cameras
• Small LCD Displays
“MPS” and “The Future of Analog IC Technology” are Registered
Trademarks of Monolithic Power Systems, Inc.
EV0022 EVALUATION BOARD
Dimensions (2.2”X x 1.5”Y x 0.5”Z)
Board Number MPS IC Number
EV0022 MP1522DT
80
70
60
50
40
30
20
10
0
EFFICIENCY (%)
0 5 10 15 20 25
LED CURRENT (mA)
Efficiency vs LED Current
2 LEDs
3 LEDs
6 LEDs
V
IN
= 3.6V
EV0022 (MP1522) — PRECISION 6 WHITE LED DRIVER EVALUATION BOARD
EV0022 Rev. 1.2 www.MonolithicPower.com 2
9/1/2006 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2006 MPS. All Rights Reserved.
EVALUATION BOARD SCHEMATIC
U1
MP1522
SW
FB
BIAS
GND
EN
2
4
3
1
5
LED1
LED2
LED3
LED4
LED5
LED6
C3
10nF
D1
B0530WS-7
J1
CN1
EV0022 BILL OF MATERIALS
Qty Ref Description Package
1 U1 MP1522 SOT23-5
1 L1 Inductor, 6.8µH D31FB
1 C1, C2 Ceramic Capacitor, 1µF, 50V, X5R or X7R 0805
1 C3 Ceramic Capacitor, 10nF, 50V, X5R or X7R 0603
1 R1 Resistor, 100kΩ, 5% 0603
1 R2 Resistor, 62Ω, 1% 0603
1 D1 Schottky Diode, 0.5A, 30V B0530W
6 LED1 – LED6 Not Included with Board
EV0022 (MP1522) — PRECISION 6 WHITE LED DRIVER EVALUATION BOARD
EV0022 Rev. 1.2 www.MonolithicPower.com 3
9/1/2006 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2006 MPS. All Rights Reserved.
PRINTED CIRCUIT BOARD LAYOUT
Figure 1—Top Silk Layer Figure 2—Top Layer
Figure 3—Bottom Layer
EV0022 (MP1522) — PRECISION 6 WHITE LED 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.
EV0022 Rev. 1.2 www.MonolithicPower.com 4
9/1/2006 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2006 MPS. All Rights Reserved.
QUICK START GUIDE
1. Connect LEDs to LED1 – LED6 terminals.
2. Preset Power Supply to 3V ≤ VCC ≤ 5.5V.
3. Turn Power Supply off.
4. Connect Power Supply terminals to:
a. Positive (+): VCC
b. Negative (–): GND
5. Turn Power Supply on after making connections.
6. Remove the jumper J1 to allow the MP1522 to automatically start when power is applied. Place
the shorting clip across J1 to disable the MP1522. A logic signal may be applied to EN to
enable/disable the MP1522, provided the shorting clip is not installed across J1.
7. To dim the LEDs remove the shorting clip from J1 and apply a PWM signal to the EN pin. The
duty cycle of the PWM signal determines the LED current.
