MP1541

EV0062 (MP1541) 1.3MHz Low Power LED Torch/Flash Driver Monolithic Power Systems EVALUATION BOARD - INITIAL RELEASE GENERAL DESCRIPTION The EV0062 is an evaluation board designed to drive up to four (4) white LEDs in series. The board is based on MPS’ MP1541 SOT23 current mode step up converter. The MP1541 is intended for small, low power applications. The MP1541 switches at 1.3MHz and allows the use of tiny, low cost capacitors and inductors 2mm or less in height. Internal soft start results in small inrush current and extends the battery life. The MP1541 operates from an input voltage as low as 2.5V and can generate 12V at up to 200mA from a 5V supply. The MP1541 includes under-voltage lockout, current limiting and thermal overload protection preventing damage in the event of an output overload. The MP1541 is available in a small 5-lead TSOT23 package. FEATURES • • • • • • • • • • • • • • • • On Board Power MOSFET Uses Tiny Capacitors and Inductors 1.3MHz Fixed Switching Frequency Internally Compensated Internal Soft Start Operates with Input Voltage as Low as 2.5V and Output Voltage as High as 22V 12V at 200mA from 5V Input UVLO, Thermal Shutdown Internal Current Limit Available in a TSOT23-5 Package Camera Phone Flash Handheld Computers and PDAs Digital Still and Video Cameras External Modems Small LCD Displays White LED Driver APPLICATIONS ELECTRICAL SPECIFICATION Parameter Supply Voltage LED Current (Torch) LED Current (Flash) Symbol VIN IOUT1 IOUT2 Value 2.5 – 6 20 100 Units V mA mA , “MPS”, “Monolithic Power Systems”, and “The Future of Analog IC Technology” are Registered Trademarks of Monolithic Power Systems, Inc. EV0062 EVALUATION BOARD Waveform in Flash Mode VFLASH 2V/Div. 0 VOUT 5V/Div. 0 (2.5”X x 2.5”Y x 0.8”Z) Board Number EV0062 Rev. B MPS IC Number MP1541 VIN = 3.6V (3 LEDs) EV0062_MP1541_TAC_EC01 06/04, Rev. 1.0 www.MonolithicPower.com 1 EV0062 (MP1541) 1.3MHz LOW POWER TORCH/FLASH LED DRIVER EVALUATION BOARD - INITIAL RELEASE EVALUATION BOARD SCHEMATIC D1 MBR0520L VOUT LED1 LED2 LED3 5 1 SW 3 FB IN EN GND VIN 5V GND GND LED4 EN 4 2 MP1541 Q1 FLASH EV0062_MP1541_SCH01 EV0062 BILL OF MATERIALS Qty 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Ref C1 C2 Description Ceramic Capacitor, 10uF, 10V, X5R Ceramic Capacitor, 1uF, 16V, X5R Schottky Diode, 0.5A, 20V Inductor, 10uH, 1.7A N-Channel Mosfet, 60V, 3A 1.3MHz Boost Converter Resistor, 100kΩ, 5% Resistor, 470kΩ, 5% Resistor, 61.9Ω, 1% Resistor, 15.4Ω, 1% Package 1210 1206 SOD-123 SOT23-6 SOT23-5 0603 0603 0603 0603 Manufacturer P/N Panasonic: ECJ-4YB1A106K Panasonic: ECJ-3YB1C105K Fairchild: MBR0520L Sumida: CDRH6D28-100NC Zetex: ZXMN6A08E6TA MPS: MP1541 Panasonic: ERJ-6ENF1003V Panasonic: ERJ-6GEYJ474V Panasonic: ERJ-6ENF61R9V Panasonic: ERJ-6ENF15R4V Distributor P/N (1) PCC2170CT-ND PCC1882CT-ND MBR0520LCT-ND ZXMN6A08E6CT-ND P100KCCT-ND P470KACT-ND P61.9CCT-ND P15.4CCT-ND D1 L1 Q1 U1 R1 R2 R3 R4 LED1 Flash LED (2) LED2 Flash LED (2) LED3 Flash LED (2) LED4 Flash LED (2) Note 1) Distributor: Digikey 2) Not included with board. 06/04, Rev. 1.0 www.MonolithicPower.com 2 EV0062 (MP1541) 1.3MHz LOW POWER TORCH/FLASH LED DRIVER EVALUATION BOARD - INITIAL RELEASE PRINTED CIRCUIT BOARD LAYOUT Figure 1—Top Silk Layer Figure 2—Top Layer Figure 3— Bottom Layer 06/04, Rev. 1.0 www.MonolithicPower.com 3 EV0062 (MP1541) 1.3MHz LOW POWER TORCH/FLASH LED DRIVER EVALUATION BOARD - INITIAL RELEASE QUICK START GUIDE 1. Connect LEDs to LED1 – LED4 terminals. 2. Preset Power Supply to 2.5V – 6V. 3. Turn Off Power Supply. 4. Connect Power Supply terminals to: a. Positive (+): VIN b. Negative (–): GND 5. Turn Power Supply On after making connections. 6. The MP1541 is automatically enabled on the demo board once VIN is applied. 7. Drive FLASH of Q1 with a pulsed signal (3V or above for High, 0V for Low) to switch between two (2) LED currents. 8. IOUT1 is set to 20mA on the board. 9. IOUT2 is set to 100mA on the board. NOTICE: MPS believes the information in this document to be accurate and reliable. However, it is subject to change without notice. Contact MPS for current specifications. MPS encourages users of its products to ensure that third party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS cannot assume any legal responsibility for any said applications. EV0062 (MP1541) Rev. 1.0 6/10/04 © 2004 MPS, Inc. Monolithic Power Systems, Inc. 983 University Avenue, Building A, Los Gatos, CA 95032 USA Tel: 408-357-6600 ♦ Fax: 408-357-6601 ♦ www.MonolithicPower.com 4