General Description

The MAX1561/MAX1599 step-up converters drive up to six white LEDs with a constant current to provide backlight in cell phones, PDAs, and other hand-held devices. The step-up converter topology allows series connection of the white LEDs so the LED currents are identical for uniform brightness. This configuration eliminates the need for ballast resistors and expensive factory calibration.

Features

♦ Accurate Current Regulation for Uniform Illumination

♦ High Efficiency Up to 87%

♦ Flexible Analog or PWM Dimming Control

♦ Up to 900mW Output Power with Internal 30V MOSFET Switch

♦ Fast 1MHz (MAX1561) or 500kHz (MAX1599) PWM Operation

♦ Small, Low-Profile External Components

♦ 2.6V to 5.5V Input Range

♦ 26V (max) Output with Overvoltage Protection

♦ Optimized for Low 15mVP-P Input Ripple

♦ Soft-Start with Zero Inrush Current

♦ 0.3µA Shutdown Current

♦ Tiny 8-Pin 3mm x 3mm Thin DFN Package

Applications

Cell Phones and Smart Phones

PDAs, Palmtops, and Wireless Handhelds

e-Books and Subnotebooks

White LED Display Backlighting