General Description
The MAX8831 integrates a 60mA, 28V PWM DC-DC step-up converter with five low-dropout LED current regulators for display and keypad backlighting in cell phones, PDAs, and other portable devices. The IC provides up to 90% efficiency over the entire input voltage range of 2.7V to 5.5V. The step-up converter operates at a fixed 2MHz switching frequency, enabling the use of very small external components to achieve a compact circuit area. For improved efficiency, the step-up converter automatically transitions to pulse-skipping mode at light loads.

Benefits and Features
• Highly Integrated 28V Step-Up DC-DC Converter with Programmable Functionality Lowers System Cost
   • Integrated NMOS Power Switch
• Two 25mA Regulators for Display Backlighting
   • I2C-Programmable 50µA to 25.25mA Output Current
   • 128-Step Logarithmic Dimming
   • Individually Programmable Ramp (Up/Down) Timers
   • Low Dropout (200mV max)
• Three 5mA Current Regulators for Keypad Lighting with I2C-Programmable 50µA to 5.0mA Output Current
   • 32-Step Logarithmic Dimming
   • Individually Programmable Ramp (Up/Down) Timers
   • Individual Blink Rate and Duty Cycle Timers
   • Low Dropout (150mV max)
   • I2C Programmable Compatible with 1.8V Logic
• Protection Features Increase Reliability
   • Open/Short LED and Open-Circuit Diode Detection
   • Thermal-Shutdown and Output Overvoltage Protection
• High Efficiency and Low Shutdown Current Extend Battery Life
   • > 90% Efficiency
   • Pulse Skipping for Improved Light-Load Efficiency
   • Ultra-Low 0.1µA Shutdown Current
• Small Solution Size Saves Board Space
   • Tiny 2mm x 2mm, 16-Bump WLP Package
   • 2MHz Switching Frequency Allows Use of Tiny External Components

Applications
   Cell Phones
   PDAs
   Smartphones