MAX1570ETE+T
Analog Devices Inc.
Price range: $2.46 - $2.79
The MAX1570 fractional charge pump drives up to five white LEDs with regulated constant current for uniform intensity. The MAX1570 maintains the highest possible efficiency over the full 1-cell lithium-ion (Li+) battery input voltage range by utilizing a 1x/1.5x fractional charge pump and very-low-dropout current regulators. The MAX1570 operates with 1MHz fixed-frequency switching, allowing for tiny external components. The regulation scheme is optimized to ensure low EMI and low input ripple. An external resistor sets the full-scale LED current, while two digital inputs control on/off and select between three levels of brightness. A pulse-width modulation (PWM) signal can also be used to modulate LED brightness.The MAX1570 is available in 16-pin 4mm x 4mm Thin QFN packaging (0.8mm max height).ApplicationsCell Phones/SmartphonesDigital Cameras and CamcordersPDAs and Palmtop ComputersPortable MP3 PlayersWhite LED Backlighting