MAX1573:White LED 1x/1.5x Charge Pump in UCSP and Thin QFN

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

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.

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
MAX1573: Typical Operating Circuit
MAX1573: Typical Operating Circuit
  • Cell Phones/Smartphones
  • MP3 Players
  • Other Handhelds with Color Displays
  • PDAs, Digital Cameras, and Camcorders
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MAX1573 Data SheetMAX1573.pdf
Part NumberBattery InputRegulation TopologyMax. No. of LEDsLED ChannelsLED ConfigurationILED per Channel
PWM Dimming Freq.
Dimming ControlPOUT
LED String Volt.
Oper. Freq.
maxmaxminmaxmaxmaxSee Notes
MAX15731-Cell Li+Charge Pump44Parallel0.02850Digital
$1.93 @1k
Design kits & evaluation modules
Quality and Environmental Data
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX1573EBE-TNo Longer AvailableUCSP,;16 pin;4.3 mm²-40°C to +85°CNo
MAX1573ETENo Longer AvailableMAX1573ETE+TQFN,;16 pin;16.8 mm²-40°C to +85°CNo
MAX1573ETE+ActiveTQFN,;16 pin;16.8 mm²-40°C to +85°CLead Free
MAX1573ETE+TActiveTQFN,;16 pin;16.8 mm²-40°C to +85°CLead Free
MAX1573ETE-TNo Longer AvailableMAX1573ETE+TQFN;16 pin-40°C to +85°CSee data sheet
MAX1573TQFNEVKITActiveEVKIT;-40°C to +85°CSee data sheet
MAX1573.pdf MAX1573
MAX1573.pdf MAX1573
MAX1573.pdf MAX1573
White-LED Driver Provides 64-Step Logarithmic Dimming DS1801
MAX1573.pdf MAX1573
MAX1573.pdf MAX1573