General Description
The MCP1603/B/L is a high-efficiency, fully-integrated 500 mA synchronous buck regulator whose 2.7V to 5.5V input voltage range makes it ideally suited for applications powered from 1-cell Li-Ion or 2-cell/3-cell NiMH/NiCd batteries.

Features
• Over 90% Typical Efficiency
• Output Current Up To 500 mA
• Low PFM Quiescent Current = 45 µA, typical
   (MCP1603/L)
• Low Shutdown Current = 0.1 µA, typical
• Adjustable Output Voltage:
   - 0.8V to 4.5V
• Fixed Output Voltage:
   - 1.2V, 1.5V, 1.8V, 2.5V, 3.3V (MCP1603/L)
   - 1.8V, 3.3V (MCP1603B)
• 2.0 MHz Fixed-Frequency PWM (Heavy Load)
• Automatic PWM-to-PFM Mode Transition
   (MCP1603/L)
• PWM Mode Only Option (MCP1603B)
• 100% Duty Cycle Operation
• Internally Compensated
• Undervoltage Lockout (UVLO)
• Overtemperature Protection
• Space Saving Packages:
   - 5-Lead TSOT, Two Pinout Types (MCP1603/L)
   - 8-Lead 2 x 3 DFN

Applications
• Cellular Telephones
• Portable Computers
• Organizers / PDAs
• USB Powered Devices
• Digital Cameras
• Portable Equipment
• +5V or +3.3V Distributed Systems
• Headsets