26V Step-Up Converters
EUP2561
for Two to Six White LEDs
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
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
RoHS Compliant and 100% Lead (Pb)-Free
APPLICATIONS
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
1