The MCP1662 device is a compact, space-efficient, fixed-frequency, non-synchronous step-up converter optimized to drive LED strings with constant current from two and three-cell alkaline and NiMH/NiCd or one-cell Li-Ion or Li-Polymer batteries.
The device integrates a 36V, 800 mΩ low-side switch, which is protected by the 1.3A cycle-by-cycle inductor peak current limit operation. Low-voltage technology allows the MCP1662 to start-up without high inrush current or output overshoot. All compensation and protection circuitry is integrated to minimize the number of external components.

• Up to 92% Efficiency
• High Output Voltage Range: up to 32V
• 1.3A Peak Input Current Limit:
  • ILEDup to 200 mA @ 5.0V VIN, 4 White LEDs
  • ILED up to 125 mA @ 3.3V VIN, 4 White LEDs
  • ILED up to 100 mA @ 4.2V VIN, 8 White LEDs
• Input Voltage Range: 2.4V to 5.5V
• Undervoltage Lockout (UVLO):
  • UVLO@VIN Rising:  2.3V, typical
  • UVLO@VIN Falling: 1.85, typical
• No Load Input Current: 250 µA, typical
• Sleep mode with 200 nA Typical Quiescent Current
• PWM Operation with Skip mode: 500 kHz
• Feedback Voltage Reference: VFB= 300 mV
• Cycle-by-Cycle Current Limiting
• Internal Compensation
• Inrush Current Limiting and Internal Soft-Start
• Output Overvoltage Protection (OVP) in the event of:
  • Feedback Pin Shorted to GND (Prevent Excessive Current into LEDs)
  • Disconnected LED String (Prevent Overvoltage to the Converter’s Output and SW Pin)
• Overtemperature Protection 
• Available Packages: 5-Lead SOT-23 or 2x3 8-Lead TDFN