MAX1848:White LED Step-Up Converter in SOT23

Current Regulated Step-Up Converter Powers White LEDs with Uniform Brightness

The MAX1848 drives 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 that the LED currents are identical for uniform brightness. This configuration eliminates the need for ballast resistors and expensive factory calibration. Other benefits include greater simplicity, lower cost, higher efficiency, and greater reliability. This step-up PWM converter includes an internal, high-voltage, low RDSON N-channel MOSFET switch for high efficiency and maximum battery life. A single analog voltage Dual Mode™ input provides a simple means of brightness adjustment and on/off control. Fast 1.2MHz current-mode PWM control 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. The MAX1848 is available in space-saving 8-pin thin QFN (3mm x 3mm) and 8-pin SOT23 packages.

Key Features
  • Constant Current Regulation for Uniform Illumination
  • High 87% Efficiency
  • Analog or Logic Control of LED Intensity
  • 0.8W Output Power with Internal High-Voltage MOSFET Switch
  • Small, Low-Profile External Components
  • 2.6V to 5.5V Input Range
  • 13V Maximum Output with Overvoltage Protection
  • Optimized for Low Input Ripple
  • Programmable Soft-Start
  • 0.3µA Shutdown Current
  • Small 8-pin Thin QFN (3mm x 3mm) and 8-Pin SOT23 Packages
MAX1848: Typical Application Circuit
MAX1848: Typical Application Circuit
  • Cell Phones/Smartphones
  • e-Books and Subnotebooks
  • PDAs, Palmtops, and Wireless Handhelds
  • White LED Display Backlighting
titleDownload file
MAX1848 Data SheetMAX1848.pdf
Part NumberBattery InputRegulation TopologyMax. No. of LEDsLED ChannelsLED ConfigurationILED per Channel
Dimming RatioDimming ControlVCURR_SENSE
LED String Volt.
Oper. Freq.
maxmaxminmaxmaxmaxSee Notes
MAX18481-Cell Li+Inductor Based61Series0.0620Analog750.82.65.52121200SOT/8
$1.32 @1k
Design kits & evaluation modules
Quality and Environmental Data
Related Products
  • MAX1698:High-Efficiency Step-Up Current Regulator for LEDs
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX1848EKA-TNo Longer AvailableSOT,;8 pin;9 mm²-40°C to +85°CNo
MAX1848ETA+ActiveTDFN-EP,;8 pin;9.6 mm²-40°C to +85°CLead Free
MAX1848ETA+TActiveTDFN-EP,;8 pin;9.6 mm²-40°C to +85°CLead Free
MAX1848ETA-TNo Longer AvailableMAX1848ETA+TTDFN-EP,;8 pin;9.6 mm²-40°C to +85°CNo
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