EV0022 (MP1522) Precision 6 White LED Driver Evaluation Board The Future of Analog IC Technology DESCRIPTION FEATURES 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. 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. ELECTRICAL SPECIFICATION Parameter Input Voltage LED Current Symbol Value Units VCC 3.0 – 5.5 20 V mA EV0022 EVALUATION BOARD Efficiency vs LED Current 80 6 LEDs 3 LEDs 2 LEDs EFFICIENCY (%) 70 Dimensions (2.2”X x 1.5”Y x 0.5”Z) Board Number MPS IC Number EV0022 MP1522DT EV0022 Rev. 1.2 9/1/2006 60 50 40 30 20 VIN = 3.6V 10 0 0 5 10 15 20 LED CURRENT (mA) www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 25 1 EV0022 (MP1522) — PRECISION 6 WHITE LED DRIVER EVALUATION BOARD EVALUATION BOARD SCHEMATIC D1 B0530WS-7 C3 10nF CN1 LED1 LED2 LED3 U1 MP1522 4 EN J1 SW BIAS 2 GND FB LED4 1 LED5 5 LED6 3 EV0022 BILL OF MATERIALS Qty 1 1 1 1 1 1 1 6 Ref U1 L1 C1, C2 C3 R1 R2 D1 LED1 – LED6 EV0022 Rev. 1.2 9/1/2006 Description MP1522 Inductor, 6.8µH Ceramic Capacitor, 1µF, 50V, X5R or X7R Ceramic Capacitor, 10nF, 50V, X5R or X7R Resistor, 100kΩ, 5% Resistor, 62Ω, 1% Schottky Diode, 0.5A, 30V Not Included with Board www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. Package SOT23-5 D31FB 0805 0603 0603 0603 B0530W 2 EV0022 (MP1522) — PRECISION 6 WHITE LED DRIVER EVALUATION BOARD PRINTED CIRCUIT BOARD LAYOUT Figure 1—Top Silk Layer Figure 2—Top Layer Figure 3—Bottom Layer EV0022 Rev. 1.2 9/1/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 3 EV0022 (MP1522) — PRECISION 6 WHITE LED DRIVER EVALUATION BOARD 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. 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 9/1/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 4