General Description

The MAX1984/MAX1985/MAX1986 are white light-emitting diode (LED) drivers that use individual regulators to control the current of up to eight LEDs. A high-efficiency step-up regulator generates just enough voltage to keep all the current regulators in regulation. A versatile dimming interface accommodates analog, digitally adjusted pulse-width modulation (DPWM), or parallel control.

Features

♦ Synchronous Step-Up Regulator

Achieves >95 Efficiency

Internal Switch and Synchronous Rectifier

Eliminates External MOSFETs and Diodes

1MHz Fixed Frequency Minimizes Component Sizes

♦ Up to 90 Total LED Efficiency

♦ Accurate LED Current Matching (8 max)

♦ Adjustable Maximum LED Current

♦ Multimode Dimming Control

Digital Pulse-Width Modulation Control

2-Bit Parallel Control

3-Bit Parallel Control

Analog Control

♦ Selectively Enable LEDs

♦ Open-LED Detection

♦ Unique 0.5mA LED Test Mode

♦ 2.7V to 5.5V Input Supply Range

♦ Small 4mm x 4mm 20-Pin Thin QFN Package

Applications

PDAs and Hand-Held PCs

Cellular Phones

Digital Cameras