
Maxim Integrated
General Description
The MAX1577Y/MAX1577Z charge pumps drive white LEDs, including camera strobes, with regulated current up to 1.2A (guaranteed to 800mA). The very low openloop output resistance allows high flash brightness, even from a low battery input voltage. The adaptive 1x/2x regulating charge-pump operation provides high efficiency (up to 92%) while in movie mode or backlighting. Fast (1MHz) switching allows the use of tiny external components.
FEATUREs
♦ Up to 1.2A Output Drive Capability (800mA
Guaranteed)
♦ Up to 92% PLED / PBATT Efficiency for Movie
Mode
♦ Flexible Brightness Control
Two-Bit Logic for 100%, 33%, 20%, and Off
PWM for 20% to 100%
♦ 3% Current Regulation Over Line and
Temperature
♦ Current or Voltage Regulation for Flash and
Backlighting (MAX1577Y)
♦ Current Regulation for Flash (MAX1577Z)
♦ Low Ripple and EMI
♦ 2.7V to 5.5V Supply Voltage Range
♦ Soft-Start Limits Inrush Current
♦ Output-Voltage Regulation Mode
♦ Thermal-Shutdown Protection
♦ 8-Pin 3mm x 3mm TDFN Package
APPLICATIONs
White LED Flashes, Strobes, and Movie Lights
LCD Backlighting
Camera Phones, Cell Phones, and Smart Phones
PDAs, Digital Cameras, and Camcorders