EUP2571 Datasheet | Eutech Microelectronics

White LED Step-Up Converter In Tiny SOT-23 Package DESCRIPTION The EUP2571 is a constant current step-up converter specifically designed to drive white LEDs. The Step-up converter topology allows series connection of the white LEDs so the LED currents are identical for uniform brightness. The EUP2571 switches at 1.1MHz, allowing the use of tiny external ponents. The input and output capacitor can be as small as 1µF, saving space and cost versus alternative solutions. A low 0.25V feedback voltage minimizes power loss in the current setting resistor for better efficiency. The EUP2571 is available in low profile SOT23-5, SOT23-6 package. Features z 2.6V to 5.5V Input Range z 26V Output with Over Voltage Protection z High Efficiency :85 % Typical z PWM Dimming Control z Internal High Power 30V MOSFET Switch z Fast 1.1MHz Switching Frequency z Small, Low-Profile Inductors and Capacitors z SOT23-5,SOT23-6 Package z Ro HS pliant and 100% Lead (Pb)-Free APPLICATIONS z Mobile Phone z Digital Still Camera z PDAs, Handheld puters z MP3 Players z GPS Receivers Typical Application Circuit DS2571 Ver1.2 Apr. 2008 Figure 1. White LED Application Typical Application Circuit (continued) Figure 2. 5V to 9V/300m A Step-Up Application Pin Configurations Package Type Pin Configurations Package Type Pin Configurations SOT23-5 SOT23-6 Pin Description PIN LX GND FB EN IN OUT SOT23-5 1 2 3 4 5 - SOT23-6 1 2 3 4 6 5 DESCRIPTION Switch Pin. Connect inductor/diode here. Minimize trace area at this pin to reduce EMI. mon Ground Feedback Pin. Reference voltage is 0.25V. Connect cathode of lowest LED and resistor here. Calculate resistor value according to the formula: RFB=0.25/ILED Chip Enable Pin. Connect to 1.4V or higher to enable device, 0.4V or less to disable device. Input Supply Voltage Overvoltage Sense. When VOUT is greater than 27V, the internal N-channel MOSFET turns off until VOUT drops below 25V, then the IC reenters start. Connect a...