High-Efficiency, 26V Step-Up Converters for Two to Six White LEDs

26V, Step-Up DC-DC Powers Up to 6 White LEDs with Up to 87% Efficiency

Please check latest availability status for a specific part variant.


The MAX1561/MAX1599 step-up converters drive up to six white LEDs with a constant current to provide backlight in cell phones, PDAs, and other hand-held devices. The step-up converter topology allows series connection of the white LEDs so the LED currents are identical for uniform brightness. This configuration eliminates the need for ballast resistors and expensive factory calibration.

The MAX1561/MAX1599 include an internal, high-voltage, low-RDS(ON) N-channel MOSFET switch for high efficiency and maximum battery life. A single Dual Mode™ input provides a simple means of brightness adjustment and on/off control. Fast 1MHz (500kHz for the MAX1599) current-mode, pulse-width modulated (PWM) operation allows for small input and output capacitors and a small inductor while minimizing ripple on the input supply/battery. Programmable soft-start eliminates inrush current during startup.

Both devices are available in a space-saving, 8-pin 3mm x 3mm thin DFN package with exposed paddle (EP).
MAX1561, MAX1599: Typical Operating Circuit MAX1561, MAX1599: Typical Operating Circuit Enlarge+

Key Features

  • Accurate Current Regulation for Uniform Illumination
  • High Efficiency Up to 87%
  • Flexible Analog or PWM Dimming Control
  • Up to 900mW Output Power with Internal 30V MOSFET Switch
  • Fast 1MHz (MAX1561) or 500kHz (MAX1599) PWM Operation
  • Small, Low-Profile External Components
  • 2.6V to 5.5V Input Range
  • 26V (max) Output with Overvoltage Protection
  • Optimized for Low 15mVP-P Input Ripple
  • Soft-Start with Zero Inrush Current
  • 0.3µA Shutdown Current
  • Tiny 8-Pin 3mm x 3mm Thin DFN Package


  • Cell Phones/Smartphones
  • e-Books and Subnotebooks
  • PDAs, Palmtops, and Wireless Handhelds
  • White LED Display Backlighting
Part Number Battery Input Regulation Topology Max. No. of LEDs LED Channels LED Configuration ILED per Channel
PWM Dimming Freq.
Dimming Control VCURR_SENSE
LED String Volt.
Oper. Freq.
Package/Pins Budgetary
max max min max max max See Notes
MAX1561  1-Cell Li+ Inductor Based 6 1 Series 0.02 200
100 0.9 2.6 5.5 0.55 26 1000
$1.29 @1k
MAX1599  500
See All LED Drivers (70)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX1561EVKIT: Evaluation Kit for MAX1561

Technical Documents

App Note 3256 Why Drive White LEDs with Constant Current?
App Note 3243 White-LED Boost Converter vs. Charge Pump
Reference Schematic 1804 Driving LEDs in Battery-Operated Applications: Controlling Brightness Power Efficiently

Quality and Environmental Data

Product Reliability Reports: MAX1561.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Additional Resources

Topmark Coding MAX1561
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >

Related Resources

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