
Maxim Integrated
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