MAX1570:White LED Current Regulator with 1x/1.5x High-Efficiency Charge Pump

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).

Key Features
  • Excellent 0.3% LED-to-LED Current Matching
  • 30mA/LED Drive Capability
  • Proprietary 1x/1.5x Modes for Ultra-High Efficiency
  • Low Input Ripple and EMI
  • Eliminates Ballast Resistors
  • Digital or PWM LED Dimming Control
  • 0.1µA Shutdown Current
  • 2.7V to 5.5V Supply Voltage Range
  • Soft-Start Limits Inrush Current
  • Thermal-Shutdown Protection
  • No External Inductor, Schottky, or Zener Diode Required
  • Tiny 16-Pin 4mm x 4mm Thin QFN Package
MAX1570: Typical Operating Circuit
MAX1570: Typical Operating Circuit
  • Cell Phones/Smartphones
  • Digital Cameras and Camcorders
  • PDAs and Palmtop Computers
  • Portable MP3 Players
  • White LED Backlighting
titleDownload file
MAX1570 Data SheetMAX1570.pdf
Part NumberBattery InputRegulation TopologyMax. No. of LEDsLED ChannelsLED ConfigurationILED per Channel
PWM Dimming Freq.
Dimming ControlPOUT
LED String Volt.
Oper. Freq.
maxmaxminmaxmaxmaxSee Notes
MAX15701-Cell Li+Charge Pump55Parallel0.035Digital
PWM$1.90 @1k
Design kits & evaluation modules
Quality and Environmental Data
Related Products
  • MAX1912:1.5x/2x High-Efficiency White LED Charge Pumps
  • MAX1910:1.5x/2x High-Efficiency White LED Charge Pumps
  • MAX1916:Low-Dropout, Constant-Current Triple White LED Bias Supply
  • MAX1595:Regulated 3.3V/5.0V Step-Up/Step-Down Charge Pump
  • MAX1848:White LED Step-Up Converter in SOT23
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX1570ETENo Longer AvailableMAX1570ETE+TQFN,;16 pin;16.8 mm²-40°C to +85°CNo
MAX1570ETE+ActiveTQFN,;16 pin;16.8 mm²-40°C to +85°CLead Free
MAX1570ETE+TActiveTQFN,;16 pin;16.8 mm²-40°C to +85°CLead Free
MAX1570ETE-TNo Longer AvailableMAX1570ETE+TQFN;16 pin-40°C to +85°CSee data sheet
MAX1570.pdf MAX1570
MAX1570.pdf MAX1570
MAX1570.pdf MAX1570
MAX1570.pdf MAX1570
MAX1570.pdf MAX1570