MP1518DG

TM EV1518DG-00A Fixed Frequency WLED Driver Evaluation Board The Future of Analog IC Technology TM 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. 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 Cell Phones Handheld Computers and PDAs Digital Still Cameras Small LCD Displays APPLICATIONS ELECTRICAL SPECIFICATIONS Parameter Input Voltage # of WLEDs LED Current Symbol VIN ILED Value 0.0 – 0.0 Up to 6 20 Units V mA “MPS” and “The Future of Analog IC Technology” are Trademarks of Monolithic Power Systems, Inc. EV1518DG-00A EVALUATION BOARD Efficiency vs LED Current 88 4 LEDS 86 EFFICIENCY (%) 84 82 80 78 6 LEDS 3 LEDS (L x W x H) 2.0” x 1.8” x 0.4” (5.0cm x 4.5cm x 1.0cm) Board Number EV1518DG-00A EV1518DG-00A Rev. 1.1 7/25/2006 VIN = 3.6V 5 10 15 LED CURRENT (mA) 20 76 MPS IC Number MP1518DG www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 1 TM EV1518DG-00A – FIXED FREQUENCY WLED DRIVER EVALUATION BOARD EVALUATION BOARD SCHEMATIC D1 BAT54WS-7 VIN LED1 2 IN U1 8 SW OV 3 6 EN GND 4 1 5 LED2 EN MP1518 GND GND NC 7 FB LED3 LED4 LED5 LED6 EV1518DG-00A BILL OF MATERIALS Qty 1 1 1 1 6 1 1 1 Ref C1 C2 D1 L1 LED1, LED2, LED3, LED4, LED5, LED6 R1 R2 U1 100kΩ 4.99Ω Value 4.7µF Description Package Manufacturer Manufacturer P/N 0805 1206 SOD-323 SMD TDK TDK Diodes Inc Sumida C2012X5R0J475M C3216X7R1H224K BAT54WS-7 CDRH3D16-220NC Ceramic Capacitor, 6.3V, X5R Ceramic Capacitor, 50V, 0.22µF X7R Diode Schottky, 30V, 200mW 22µH 400mA Not Stuffed Resistor, 5% Resistor, 1% White Led Driver 0805 0805 QFN8 (2x2) Panasonic Yageo MPS ERJ-6GEYJ104V 9C08052A4R99FKHFT MP1518DG EV1518DG-00A Rev. 1.1 7/25/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 2 TM EV1518DG-00A – FIXED FREQUENCY WLED DRIVER EVALUATION BOARD 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. 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. 1.1 7/25/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 3