TM EV0035 6 White LEDs, 20mA Precision WLED Driver Evaluation Board The Future of Analog IC Technology TM DESCRIPTION FEATURES The EV0035 is the evaluation board for the MP1523, which is designed for driving up to six (6) series WLEDs from a single cell Lithium Ion battery. The board is set up to obtain 20mA LED current. The current can be adjusted by varying the resistor R2. • • • • The MP1523 uses current limited, variable frequency architecture to regulate the LED current while maintaining high efficiency. The BIAS pin measures the output voltage and turns off the converter if an over voltage condition is present to prevent damage due to an open circuit condition. The LED current is measured with an external current sense resistor. The low 0.4V full-scale regulation threshold and 0.5Ω power switch minimize power loss to improve efficiency. • • • • 2.7V to 25V Input Voltage Range Drives up to 6 Series White LEDs Surface-Mount Components Fully Assembled and Tested APPLICATIONS Cell Phones Handheld Computers and PDAs Digital Still and Video Cameras Small LCD Displays “MPS” and “The Future of Analog IC Technology” are Trademarks of Monolithic Power Systems, Inc. ELECTRICAL SPECIFICATIONS Parameter Input Voltage # of WLEDs LED Current Symbol Value Units VIN 2.7 – 25 up to 6 20 V ILED mA EV0035 EVALUATION BOARD Efficiency vs VIN EFFICIENCY (%) 85 (L x W x H) 2.0” x 1.4” x 0.5” (5.0cm x 3.5 x 1.2cm) Board Number MPS IC Number EV0035 MP1523DT EV0035 Rev. 1.2 3/30/2006 80 75 70 2.5 3.0 3.5 VIN (V) www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 4.0 4.5 EV0035_AC01 1 TM EV0035 – 6 WHITE LEDs, 20mA PRECISION WLED DRIVER EVALUATION BOARD EVALUATION BOARD SCHEMATIC D1 MBR0540 VCC GND LED1 U1 4 EN J1 EN SW MP1523 GND BIAS 2 GND FB 1 LED2 5 C3 10nF 3 LED3 LED4 LED5 LED6 EV0035_S01 EV0035 BILL OF MATERIALS Qty Ref Value Description 2 1 C1, C2 C3 1µF 10nF Ceramic Cap., 50V, X7R Ceramic Cap., 50V, X7R 1 D1 6 1 1 1 1 LED1 to LED6 L1 R1 R2 U1 EV0035 Rev. 1.2 3/30/2006 Diode Schottky, 40V, 500mA Package Manufacturer Part Number 1206 0603 TDK C3216X7R1H105K TDK C1608X7R1H103K ON MBR0540T1 SOD-123 Semiconductor Not Stuffed 15µH 100kΩ 20Ω Inductor, 450mA Film Res., 5% Film Res., 5% White LED Driver SMD 0603 0603 SOT23-5 Sumida Panasonic Panasonic MPS www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. CDRH3D16-150NC ERJ-3GEYJ104V ERJ-3GEYJ200V MP1523DT 2 TM EV0035 – 6 WHITE LEDs, 20mA PRECISION WLED DRIVER EVALUATION BOARD PRINTED CIRCUIT BOARD LAYOUT Figure 1—Top Silk Layer Figure 2—Top Layer Figure 3—Bottom Layer EV0035 Rev. 1.2 3/30/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 3 TM EV0035 – 6 WHITE LEDs, 20mA PRECISION WLED DRIVER EVALUATION BOARD QUICK START GUIDE 1. 2. 3. 4. Solder LED1 – LED6 onto the board. Connect VCC to the power source’s positive output. Connect GND to supply ground. Remove the jumper J1 to allow the MP1523 to automatically start when power is applied. Place the shorting clip across J1 to disable the MP1523. A logic signal may be applied to EN to enable/disable the MP1523, provided the shorting clip is not installed across J1. 5. To dim the LEDs, remove the shorting clip from J1 and apply a PWM signal to the EN pin. Adjusting the duty cycle of the PWM signal determines the brightness of the LEDs. NOTICE: The information in this document is subject to change without notice. Please contact MPS for current specifications. 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. EV0035 Rev. 1.2 3/30/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 4