EUP2561 Datasheet | Eutech Microelectronics

DESCRIPTION The EUP2561 is a constant current step-up converter specially designed for driving white LEDs. The step-up converter topology allows series connection of the white LEDs so the LED currents are identical for uniform brightness. The EUP2561 can drive 6 LEDs in series. The brightness of the LEDs can be adjusted through a voltage level on the CTRL pin or by applying a PWM signal to CRTL pin. 1MHz current-mode, pulse-width modulated (PWM) operation allows for small input and output capacitors .. and a small inductor while minimizing ripple on the input supply/battery. Programmable soft-start eliminates inrush current during startup. The EUP2561 is available in a space-saving, 8-pin 3mm x 3mm DFN package. FEATURES z z z z z z z z z z 2.6V to 5.5V Input Range 26V (max) Output with Overvoltage Protection Up to 87% Efficiency Flexible Analog or PWM Dimming Control Internal High Power 30V MOSFET Switch < 1µA shutdown Current Fast 1MHz PWM Operation Small, Low-Profile Inductors and Capacitors 3mm × 3mm DFN-8 Package Ro HS pliant and 100% Lead (Pb)-Free APPLICATIONS z z z z Cell Phones and Smart Phones PDAs, Palmtops, and Wireless Handhelds e-Books and Subnotebooks White LED Display Backlighting Typical Application Circuit Figure 1. White LED Application DS2561 Ver1.0 Dec. 2006 Pin Configurations Package Type Pin Configurations (Top View) DFN-8 .. Pin Description PIN OUT IN CTRL CS P GND PGND LX Pin 1 2 3 4 5 6 7 8 Regulated Output Voltage. Input Supply Voltage. Brightness Control Input. LED brightness is controlled by the voltage applied to CTRL. Varying the voltage from 0.24V to 1.62V adjusts the brightness from dim to bright, respectively. Any voltage above 1.62V does not increase brightness. Current-Sense Feedback Input. Connect a resistor from CS to GND to set the LED bias current. The voltage at CS regulates to VCTRL / 10 or 0.162V, whichever is lower. pensation Input. Connect a 0.1µF capacitor (CP) from P to GND. CP stabilizes the converter...