
Maxim Integrated
General Description
The MAX1707 provides complete light management for main display backlight, subdisplay backlight (or RGB indicator), and white LED camera flash with regulated constant current up to 610mA total. By utilizing adaptive 1x/1.5x/2x charge-pump modes and very-lowdropout current regulators, it achieves high efficiency over the full 1-cell Li+ battery input voltage range. The 1MHz fixed-frequency switching allows for tiny external components while the regulation scheme is optimized to ensure low EMI and low input ripple. An integrated derating function protects the LEDs from overheating during high ambient temperatures.
FEATUREs
♦ Guaranteed 610mA Continuous Drive Capability
4 LEDs at 30mA Each for Main Display
3 LEDs at 30mA Each for Sub or RGB
400mA Total for Flash
♦ 2-Wire I2C Serial Port
5-Bit (32-Step) Linear Dimming
32k Colors
Ramp-Up/Down Rates
♦ 92% Peak/83% Avg Efficiency (PLED/PBATT)
♦ Adaptive 1x/1.5x/2x Mode Switchover
♦ 0.3% (typ) LED Current Accuracy and Matching
♦ Low Input Ripple and EMI
♦ Low 0.1µA Shutdown Current
♦ Output Overvoltage Protection
♦ Thermal Derating Function Protects LEDs
♦ 24-Pin 4mm x 4mm Thin QFN Package
APPLICATIONs
Cell Phones and Smartphones
PDAs, Digital Cameras, Camcorders
Displays with Up to 11 LEDs