General Description

The MAX8901A/MAX8901B step-up converters drive from two to six series-connected white LEDs (WLEDs) with constant current to provide uniform WLED intensity for LCD backlighting in cell phones, PDAs, and other handheld devices. The MAX8901_ operate at a fixed 750kHz (typ) switching frequency, allowing for tiny external components, and are optimized for the highest possible efficiency over the full 1-cell Li+/Li-Poly battery range.

Benefits and Features

• Cost-Effective and Flexible Solution for Wide Range of Backlighting Applications

   • Supplies from 2 to 6 WLEDs with 1.3 LED Current Accuracy

   • 2.6V to 5.5V Input Voltage Range

   • Fixed-Frequency Operation

   • Flexible Dimming Control

   • Direct PWM Dimming (MAX8901A)

   • 32-Step, Single-Wire Serial Dimming (MAX8901B)

• Protection Features Improve System Reliability

   • WLED Overvoltage Protection (25V typ)

   • Internal Soft-Start and Thermal Shutdown

   • Input Undervoltage Lockout

   • Input Overvoltage Lockout

• High Efficiency Extends Battery Life

   • Up to 91 Efficiency

   • 0.01µA (typ) Shutdown Current

   • No WLED Current in Shutdown

• 8-Pin, 2mm x 2mm TDFN Package Saves Space

Applications

   Display Backlight (from 2 to 6 WLEDs)

   Cellular Phones

   PDAs and Smartphones

   MP3 and Portable Media Players

   Portable Navigation Devices

   Digital Cameras