MAX1573 Evaluation Kit

The MAX1573EBE-T 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 MAX1573EBE-T is available in the tiny chip-scale UCSP (4 x 4 grid) packages.

• 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) Packages