White LED 1x/1.5x Charge Pump in UCSP and Thin QFN

Smallest, Highest Efficiency White LED Charge Pump Packaged in a UCSP™

Please check latest availability status for a specific part variant.


The MAX1573 fractional charge pump drives up to four white LEDs with regulated constant current for uniform intensity. By utilizing proprietary adaptive 1x/1.5x modes and ultra-low-dropout current regulators, it maintains the highest possible efficiency over the full 1-cell Li+ battery input voltage range. The 1MHz fixed-frequency switching allows for tiny external components and 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 amongst three levels of brightness. A pulse-width modulation (PWM) signal can also be used to modulate LED brightness, requiring no additional components.

The MAX1573 is available in the tiny chip-scale UCSP™ (4 x 4 grid) and 16-pin thin QFN packages.
MAX1573: Typical Operating Circuit MAX1573: Typical Operating Circuit Enlarge+

Key Features

  • Proprietary Adaptive 1x/1.5x Modes
  • High Efficiency (PLEDs/PBATT), Up to 92%
  • 0.2% LED Current Matching
  • 28mA/LED Drive Capability
  • Low Input Ripple and EMI
  • Eliminates Ballast Resistors
  • Logic or PWM Dimming Control
  • Low 0.1µA Shutdown Current
  • 2.7V to 5.5V Input Voltage Range
  • Soft-Start Limits Inrush Current
  • Output Overvoltage Protection
  • Thermal Shutdown Protection
  • No External Schottky Diode Required
  • Tiny UCSP (2.1mm x 2.1mm x 0.6mm) and Thin QFN (4mm x 4mm) Packages


  • Cell Phones/Smartphones
  • MP3 Players
  • Other Handhelds with Color Displays
  • PDAs, Digital Cameras, and Camcorders

See parametric specs for LED Drivers (83)

Part NumberVIN
Max. No. of LEDs# LED ChannelsRegulation Topology
MAX1573 2.75.544Charge Pump

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.

MAX1573EVKIT: Evaluation Kit for the MAX1573
Product Reliability Reports: MAX1573.pdf 
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

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.

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